Mostly complete implementation of the 'c' (character available)

[mandoc.git] / roff.7

diff --git a/roff.7 b/roff.7
index c8c37cc03070f279c30febbb363470b746351a64..5bf3ed25869da921129cb59a9db47a4126523eaa 100644 (file)
--- a/roff.7
+++ b/roff.7
@@ -1,7 +1,7 @@
-.\"    $Id: roff.7,v 1.65 2015/01/21 20:33:25 schwarze Exp $
+.\"    $Id: roff.7,v 1.101 2018/08/19 17:46:14 schwarze Exp $

 .\"
 .\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"
 .\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>

-.\" Copyright (c) 2010, 2011, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2010-2018 Ingo Schwarze <schwarze@openbsd.org>

 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above


@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"

-.Dd $Mdocdate: January 21 2015 $
+.Dd $Mdocdate: August 19 2018 $

 .Dt ROFF 7
 .Os
 .Sh NAME
 .Dt ROFF 7
 .Os
 .Sh NAME


@@ -86,13 +86,9 @@ character, and, in certain circumstances, the tab character.
 The backslash character
 .Sq \e
 indicates the start of an escape sequence, used for example for
 The backslash character
 .Sq \e
 indicates the start of an escape sequence, used for example for

-.Sx Comments ,
-.Sx Special Characters ,
-.Sx Predefined Strings ,
+.Sx Comments

 and
 and

-user-defined strings defined using the
-.Sx ds
-request.
+.Sx Special Characters .

 For a listing of escape sequences, consult the
 .Sx ESCAPE SEQUENCE REFERENCE
 below.
 For a listing of escape sequences, consult the
 .Sx ESCAPE SEQUENCE REFERENCE
 below.


@@ -169,34 +165,6 @@ Text decoration is
 recommended for
 .Xr mdoc 7 ,
 which encourages semantic annotation.
 recommended for
 .Xr mdoc 7 ,
 which encourages semantic annotation.

-.Ss Predefined Strings
-Predefined strings, like
-.Sx Special Characters ,
-mark special output glyphs.
-Predefined strings are escaped with the slash-asterisk,
-.Sq \e* :
-single-character
-.Sq \e*X ,
-two-character
-.Sq \e*(XX ,
-and N-character
-.Sq \e*[N] .
-.Pp
-Examples:
-.Bl -tag -width Ds -offset indent -compact
-.It Li \e*(Am
-Two-letter ampersand predefined string.
-.It Li \e*q
-One-letter double-quote predefined string.
-.El
-.Pp
-Predefined strings are not recommended for use,
-as they differ across implementations.
-Those supported by
-.Xr mandoc 1
-are listed in
-.Xr mandoc_char 7 .
-Manuals using these predefined strings are almost certainly not portable.

 .Ss Whitespace
 Whitespace consists of the space character.
 In text lines, whitespace is preserved within a line.
 .Ss Whitespace
 Whitespace consists of the space character.
 In text lines, whitespace is preserved within a line.


@@ -206,7 +174,7 @@ Unescaped trailing spaces are stripped from text line input unless in a
 literal context.
 In general, trailing whitespace on any input line is discouraged for
 reasons of portability.
 literal context.
 In general, trailing whitespace on any input line is discouraged for
 reasons of portability.

-In the rare case that a blank character is needed at the end of an
+In the rare case that a space character is needed at the end of an

 input line, it may be forced by
 .Sq \e\ \e& .
 .Pp
 input line, it may be forced by
 .Sq \e\ \e& .
 .Pp


@@ -397,219 +365,218 @@ The
 parser recognises the following requests.
 For requests marked as "ignored" or "unsupported", any arguments are
 ignored, and the number of arguments is not checked.
 parser recognises the following requests.
 For requests marked as "ignored" or "unsupported", any arguments are
 ignored, and the number of arguments is not checked.

-.Ss \&ab
+.Bl -tag -width Ds
+.It Ic \&ab Op Ar message

 Abort processing.
 Currently unsupported.
 Abort processing.
 Currently unsupported.

-.Ss \&ad
-Set line adjustment mode.
-It takes one argument to select normal, left, right,
-or center adjustment for subsequent text.
+.It Ic \&ad Op Cm b | c | l | n | r
+Set line adjustment mode for subsequent text.

 Currently ignored.
 Currently ignored.

-.Ss \&af
+.It Ic \&af Ar registername format

 Assign an output format to a number register.
 Currently ignored.
 Assign an output format to a number register.
 Currently ignored.

-.Ss \&aln
+.It Ic \&aln Ar newname oldname

 Create an alias for a number register.
 Currently unsupported.
 Create an alias for a number register.
 Currently unsupported.

-.Ss \&als
+.It Ic \&als Ar newname oldname

 Create an alias for a request, string, macro, or diversion.
 Create an alias for a request, string, macro, or diversion.

-Currently unsupported.
-.Ss \&am
+.It Ic \&am Ar macroname Op Ar endmacro

 Append to a macro definition.
 The syntax of this request is the same as that of
 Append to a macro definition.
 The syntax of this request is the same as that of

-.Sx \&de .
-.Ss \&am1
+.Ic \&de .
+.It Ic \&am1 Ar macroname Op Ar endmacro

 Append to a macro definition, switching roff compatibility mode off
 during macro execution (groff extension).
 The syntax of this request is the same as that of
 Append to a macro definition, switching roff compatibility mode off
 during macro execution (groff extension).
 The syntax of this request is the same as that of

-.Sx \&de1 .
+.Ic \&de1 .

 Since
 .Xr mandoc 1
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for
 Since
 .Xr mandoc 1
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for

-.Sx \&am .
-.Ss \&ami
+.Ic \&am .
+.It Ic \&ami Ar macrostring Op Ar endstring

 Append to a macro definition, specifying the macro name indirectly
 (groff extension).
 The syntax of this request is the same as that of
 Append to a macro definition, specifying the macro name indirectly
 (groff extension).
 The syntax of this request is the same as that of

-.Sx \&dei .
-.Ss \&ami1
+.Ic \&dei .
+.It Ic \&ami1 Ar macrostring Op Ar endstring

 Append to a macro definition, specifying the macro name indirectly
 and switching roff compatibility mode off during macro execution
 (groff extension).
 The syntax of this request is the same as that of
 Append to a macro definition, specifying the macro name indirectly
 and switching roff compatibility mode off during macro execution
 (groff extension).
 The syntax of this request is the same as that of

-.Sx \&dei1 .
+.Ic \&dei1 .

 Since
 .Xr mandoc 1
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for
 Since
 .Xr mandoc 1
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for

-.Sx \&ami .
-.Ss \&as
+.Ic \&ami .
+.It Ic \&as Ar stringname Op Ar string

 Append to a user-defined string.
 The syntax of this request is the same as that of
 .Sx \&ds .
 If a user-defined string with the specified name does not yet exist,
 it is set to the empty string before appending.
 Append to a user-defined string.
 The syntax of this request is the same as that of
 .Sx \&ds .
 If a user-defined string with the specified name does not yet exist,
 it is set to the empty string before appending.

-.Ss \&as1
+.It Ic \&as1 Ar stringname Op Ar string

 Append to a user-defined string, switching roff compatibility mode off
 during macro execution (groff extension).
 The syntax of this request is the same as that of
 Append to a user-defined string, switching roff compatibility mode off
 during macro execution (groff extension).
 The syntax of this request is the same as that of

-.Sx \&ds1 .
+.Ic \&ds1 .

 Since
 .Xr mandoc 1
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for
 Since
 .Xr mandoc 1
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for

-.Sx \&as .
-.Ss \&asciify
+.Ic \&as .
+.It Ic \&asciify Ar divname

 Fully unformat a diversion.
 Currently unsupported.
 Fully unformat a diversion.
 Currently unsupported.

-.Ss \&backtrace
+.It Ic \&backtrace

 Print a backtrace of the input stack.
 This is a groff extension and currently ignored.
 Print a backtrace of the input stack.
 This is a groff extension and currently ignored.

-.Ss \&bd
+.It Ic \&bd Ar font Oo Ar curfont Oc Op Ar offset

 Artificially embolden by repeated printing with small shifts.
 Currently ignored.
 Artificially embolden by repeated printing with small shifts.
 Currently ignored.

-.Ss \&bleedat
+.It Ic \&bleedat Ar left top width height

 Set the BleedBox page parameter for PDF generation.
 This is a Heirloom extension and currently ignored.
 Set the BleedBox page parameter for PDF generation.
 This is a Heirloom extension and currently ignored.

-.Ss \&blm
+.It Ic \&blm Ar macroname

 Set a blank line trap.
 Currently unsupported.
 Set a blank line trap.
 Currently unsupported.

-.Ss \&box
+.It Ic \&box Ar divname

 Begin a diversion without including a partially filled line.
 Currently unsupported.
 Begin a diversion without including a partially filled line.
 Currently unsupported.

-.Ss \&boxa
+.It Ic \&boxa Ar divname

 Add to a diversion without including a partially filled line.
 Currently unsupported.
 Add to a diversion without including a partially filled line.
 Currently unsupported.

-.Ss \&bp
-Begin new page.
+.It Ic \&bp Oo Cm + Ns | Ns Cm - Oc Ns Ar pagenumber
+Begin a new page.

 Currently ignored.
 Currently ignored.

-.Ss \&BP
+.It Ic \&BP Ar source height width position offset flags label

 Define a frame and place a picture in it.
 This is a Heirloom extension and currently unsupported.
 Define a frame and place a picture in it.
 This is a Heirloom extension and currently unsupported.

-.Ss \&br
+.It Ic \&br

 Break the output line.
 Break the output line.

-See
-.Xr man 7
-and
-.Xr mdoc 7 .
-.Ss \&break
+.It Ic \&break

 Break out of a
 Break out of a

-.Sx \&while
+.Ic \&while

 loop.
 Currently unsupported.
 loop.
 Currently unsupported.

-.Ss \&breakchar
+.It Ic \&breakchar Ar char ...

 Optional line break characters.
 This is a Heirloom extension and currently ignored.
 Optional line break characters.
 This is a Heirloom extension and currently ignored.

-.Ss \&brnl
-Break output line after next N input lines.
+.It Ic \&brnl Ar N
+Break output line after the next
+.Ar N
+input lines.

 This is a Heirloom extension and currently ignored.
 This is a Heirloom extension and currently ignored.

-.Ss \&brp
+.It Ic \&brp

 Break and spread output line.
 Currently, this is implemented as an alias for
 Break and spread output line.
 Currently, this is implemented as an alias for

-.Sx \&br .
-.Ss \&brpnl
-Break and spread output line after next N input lines.
+.Ic \&br .
+.It Ic \&brpnl Ar N
+Break and spread output line after the next
+.Ar N
+input lines.

 This is a Heirloom extension and currently ignored.
 This is a Heirloom extension and currently ignored.

-.Ss \&c2
+.It Ic \&c2 Op Ar char

 Change the no-break control character.
 Currently unsupported.
 Change the no-break control character.
 Currently unsupported.

-.Ss \&cc
+.It Ic \&cc Op Ar char

 Change the control character.
 Change the control character.

-Its syntax is as follows:
-.Bd -literal -offset indent
-.Pf . Cm \&cc Op Ar c
-.Ed
-.Pp

 If
 If

-.Ar c
+.Ar char

 is not specified, the control character is reset to
 .Sq \&. .
 Trailing characters are ignored.
 is not specified, the control character is reset to
 .Sq \&. .
 Trailing characters are ignored.

-.Ss \&ce
-Center some lines.
-It takes one integer argument, specifying how many lines to center.
-Currently ignored.
-.Ss \&cf
+.It Ic \&ce Op Ar N
+Center the next
+.Ar N
+input lines without filling.
+.Ar N
+defaults to 1.
+An argument of 0 or less ends centering.
+Currently, high level macros abort centering.
+.It Ic \&cf Ar filename

 Output the contents of a file.
 Ignored because insecure.
 Output the contents of a file.
 Ignored because insecure.

-.Ss \&cflags
+.It Ic \&cflags Ar flags char ...

 Set character flags.
 This is a groff extension and currently ignored.
 Set character flags.
 This is a groff extension and currently ignored.

-.Ss \&ch
+.It Ic \&ch Ar macroname Op Ar dist

 Change a trap location.
 Currently ignored.
 Change a trap location.
 Currently ignored.

-.Ss \&char
+.It Ic \&char Ar glyphname Op Ar string

 Define a new glyph.
 Currently unsupported.
 Define a new glyph.
 Currently unsupported.

-.Ss \&chop
+.It Ic \&chop Ar stringname

 Remove the last character from a macro, string, or diversion.
 Currently unsupported.
 Remove the last character from a macro, string, or diversion.
 Currently unsupported.

-.Ss \&class
+.It Ic \&class Ar classname char ...

 Define a character class.
 This is a groff extension and currently ignored.
 Define a character class.
 This is a groff extension and currently ignored.

-.Ss \&close
+.It Ic \&close Ar streamname

 Close an open file.
 Ignored because insecure.
 Close an open file.
 Ignored because insecure.

-.Ss \&CL
+.It Ic \&CL Ar color text

 Print text in color.
 This is a Heirloom extension and currently unsupported.
 Print text in color.
 This is a Heirloom extension and currently unsupported.

-.Ss \&color
+.It Ic \&color Op Cm 1 | 0

 Activate or deactivate colors.
 This is a groff extension and currently ignored.
 Activate or deactivate colors.
 This is a groff extension and currently ignored.

-.Ss \&composite
+.It Ic \&composite Ar from to

 Define a name component for composite glyph names.
 This is a groff extension and currently unsupported.
 Define a name component for composite glyph names.
 This is a groff extension and currently unsupported.

-.Ss \&continue
+.It Ic \&continue

 Immediately start the next iteration of a
 Immediately start the next iteration of a

-.Sx \&while
+.Ic \&while

 loop.
 Currently unsupported.
 loop.
 Currently unsupported.

-.Ss \&cp
+.It Ic \&cp Op Cm 1 | 0

 Switch
 .Nm
 compatibility mode on or off.
 Currently ignored.
 Switch
 .Nm
 compatibility mode on or off.
 Currently ignored.

-.Ss \&cropat
+.It Ic \&cropat Ar left top width height

 Set the CropBox page parameter for PDF generation.
 This is a Heirloom extension and currently ignored.
 Set the CropBox page parameter for PDF generation.
 This is a Heirloom extension and currently ignored.

-.Ss \&cs
+.It Ic \&cs Ar font Op Ar width Op Ar emsize

 Constant character spacing mode.
 Currently ignored.
 Constant character spacing mode.
 Currently ignored.

-.Ss \&cu
-Underline including whitespace.
+.It Ic \&cu Op Ar N
+Underline next
+.Ar N
+input lines including whitespace.

 Currently ignored.
 Currently ignored.

-.Ss \&da
+.It Ic \&da Ar divname

 Append to a diversion.
 Currently unsupported.
 Append to a diversion.
 Currently unsupported.

-.Ss \&dch
+.It Ic \&dch Ar macroname Op Ar dist

 Change a trap location in the current diversion.
 This is a Heirloom extension and currently unsupported.
 Change a trap location in the current diversion.
 This is a Heirloom extension and currently unsupported.

-.Ss \&de
+.It Ic \&de Ar macroname Op Ar endmacro

 Define a
 .Nm
 macro.
 Its syntax can be either
 .Bd -literal -offset indent
 Define a
 .Nm
 macro.
 Its syntax can be either
 .Bd -literal -offset indent

-.Pf . Cm \&de Ar name
-.Ar macro definition
+.Pf . Ic \&de Ar macroname
+.Ar definition

 \&..
 .Ed
 .Pp
 or
 .Bd -literal -offset indent
 \&..
 .Ed
 .Pp
 or
 .Bd -literal -offset indent

-.Pf . Cm \&de Ar name Ar end
-.Ar macro definition
-.Pf . Ar end
+.Pf . Ic \&de Ar macroname Ar endmacro
+.Ar definition
+.Pf . Ar endmacro

 .Ed
 .Pp
 Both forms define or redefine the macro
 .Ed
 .Pp
 Both forms define or redefine the macro

-.Ar name
+.Ar macroname

 to represent the
 to represent the

-.Ar macro definition ,
+.Ar definition ,

 which may consist of one or more input lines, including the newline
 characters terminating each line, optionally containing calls to
 .Nm
 which may consist of one or more input lines, including the newline
 characters terminating each line, optionally containing calls to
 .Nm


@@ -622,13 +589,13 @@ or
 macros, whichever applies to the document in question.
 .Pp
 Specifying a custom
 macros, whichever applies to the document in question.
 .Pp
 Specifying a custom

-.Ar end
+.Ar endmacro

 macro works in the same way as for
 macro works in the same way as for

-.Sx \&ig ;
+.Ic \&ig ;

 namely, the call to
 namely, the call to

-.Sq Pf . Ar end
+.Sq Pf . Ar endmacro

 first ends the
 first ends the

-.Ar macro definition ,
+.Ar definition ,

 and after that, it is also evaluated as a
 .Nm
 request or
 and after that, it is also evaluated as a
 .Nm
 request or


@@ -637,7 +604,7 @@ macro, but not as a high-level macro.
 .Pp
 The macro can be invoked later using the syntax
 .Pp
 .Pp
 The macro can be invoked later using the syntax
 .Pp

-.D1 Pf . Ar name Op Ar argument Op Ar argument ...
+.D1 Pf . Ar macroname Op Ar argument Op Ar argument ...

 .Pp
 Regarding argument parsing, see
 .Sx MACRO SYNTAX
 .Pp
 Regarding argument parsing, see
 .Sx MACRO SYNTAX


@@ -645,7 +612,7 @@ above.
 .Pp
 The line invoking the macro will be replaced
 in the input stream by the
 .Pp
 The line invoking the macro will be replaced
 in the input stream by the

-.Ar macro definition ,
+.Ar definition ,

 replacing all occurrences of
 .No \e\e$ Ns Ar N ,
 where
 replacing all occurrences of
 .No \e\e$ Ns Ar N ,
 where


@@ -665,18 +632,20 @@ produces
 .D1 \efI\e^XtFree\e^\efP.
 .Pp
 in the input stream, and thus in the output: \fI\^XtFree\^\fP.
 .D1 \efI\e^XtFree\e^\efP.
 .Pp
 in the input stream, and thus in the output: \fI\^XtFree\^\fP.

+Each occurrence of \e\e$* is replaced with all the arguments,
+joined together with single space characters.

 .Pp
 Since macros and user-defined strings share a common string table,
 defining a macro
 .Pp
 Since macros and user-defined strings share a common string table,
 defining a macro

-.Ar name
+.Ar macroname

 clobbers the user-defined string
 clobbers the user-defined string

-.Ar name ,
+.Ar macroname ,

 and the
 and the

-.Ar macro definition
+.Ar definition

 can also be printed using the
 .Sq \e*
 string interpolation syntax described below
 can also be printed using the
 .Sq \e*
 string interpolation syntax described below

-.Sx ds ,
+.Ic ds ,

 but this is rarely useful because every macro definition contains at least
 one explicit newline character.
 .Pp
 but this is rarely useful because every macro definition contains at least
 one explicit newline character.
 .Pp


@@ -687,7 +656,7 @@ to a large, but finite number, and
 .Xr mandoc 1
 also limits the length of the expanded input line.
 Do not rely on the exact values of these limits.
 .Xr mandoc 1
 also limits the length of the expanded input line.
 Do not rely on the exact values of these limits.

-.Ss \&de1
+.It Ic \&de1 Ar macroname Op Ar endmacro

 Define a
 .Nm
 macro that will be executed with
 Define a
 .Nm
 macro that will be executed with


@@ -699,24 +668,20 @@ Since
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for

-.Sx \&de .
-.Ss \&defcolor
+.Ic \&de .
+.It Ic \&defcolor Ar newname scheme component ...

 Define a color name.
 This is a groff extension and currently ignored.
 Define a color name.
 This is a groff extension and currently ignored.

-.Ss \&dei
+.It Ic \&dei Ar macrostring Op Ar endstring

 Define a
 .Nm
 macro, specifying the macro name indirectly (groff extension).
 The syntax of this request is the same as that of
 Define a
 .Nm
 macro, specifying the macro name indirectly (groff extension).
 The syntax of this request is the same as that of

-.Sx \&de .
-The request
-.Pp
-.D1 Pf . Cm \&dei Ar name Op Ar end
-.Pp
-has the same effect as:
+.Ic \&de .
+The effect is the same as:

 .Pp
 .Pp

-.D1 Pf . Cm \&de No \e* Ns Bo Ar name Bc Op \e* Ns Bq Ar end
-.Ss \&dei1
+.D1 Pf . Cm \&de No \e* Ns Bo Ar macrostring Bc Op \e* Ns Bq Ar endstring
+.It Ic \&dei1 Ar macrostring Op Ar endstring

 Define a
 .Nm
 macro that will be executed with
 Define a
 .Nm
 macro that will be executed with


@@ -728,29 +693,23 @@ Since
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for

-.Sx \&dei .
-.Ss \&device
-This request only makes sense with the groff-specific intermediate
-output format and is unsupported.
-.Ss \&devicem
-This request only makes sense with the groff-specific intermediate
-output format and is unsupported.
-.Ss \&di
+.Ic \&dei .
+.It Ic \&device Ar string ...
+.It Ic \&devicem Ar stringname
+These two requests only make sense with the groff-specific intermediate
+output format and are unsupported.
+.It Ic \&di Ar divname

 Begin a diversion.
 Currently unsupported.
 Begin a diversion.
 Currently unsupported.

-.Ss \&do
+.It Ic \&do Ar command Op Ar argument ...

 Execute
 .Nm
 request or macro line with compatibility mode disabled.
 Currently unsupported.
 Execute
 .Nm
 request or macro line with compatibility mode disabled.
 Currently unsupported.

-.Ss \&ds
+.It Ic \&ds Ar stringname Op Oo \(dq Oc Ns Ar string

 Define a user-defined string.
 Define a user-defined string.

-Its syntax is as follows:
-.Pp
-.D1 Pf . Cm \&ds Ar name Oo \(dq Oc Ns Ar string
-.Pp

 The
 The

-.Ar name
+.Ar stringname

 and
 .Ar string
 arguments are space-separated.
 and
 .Ar string
 arguments are space-separated.


@@ -765,11 +724,11 @@ including whitespace and double-quote characters, even trailing ones.
 The
 .Ar string
 can be interpolated into subsequent text by using
 The
 .Ar string
 can be interpolated into subsequent text by using

-.No \e* Ns Bq Ar name
+.No \e* Ns Bq Ar stringname

 for a
 for a

-.Ar name
+.Ar stringname

 of arbitrary length, or \e*(NN or \e*N if the length of
 of arbitrary length, or \e*(NN or \e*N if the length of

-.Ar name
+.Ar stringname

 is two or one characters, respectively.
 Interpolation can be prevented by escaping the leading backslash;
 that is, an asterisk preceded by an even number of backslashes
 is two or one characters, respectively.
 Interpolation can be prevented by escaping the leading backslash;
 that is, an asterisk preceded by an even number of backslashes


@@ -777,11 +736,11 @@ does not trigger string interpolation.
 .Pp
 Since user-defined strings and macros share a common string table,
 defining a string
 .Pp
 Since user-defined strings and macros share a common string table,
 defining a string

-.Ar name
+.Ar stringname

 clobbers the macro
 clobbers the macro

-.Ar name ,
+.Ar stringname ,

 and the
 and the

-.Ar name
+.Ar stringname

 used for defining a string can also be invoked as a macro,
 in which case the following input line will be appended to the
 .Ar string ,
 used for defining a string can also be invoked as a macro,
 in which case the following input line will be appended to the
 .Ar string ,


@@ -796,12 +755,12 @@ H SYNOPSIS
 .Ed
 .Pp
 invokes the
 .Ed
 .Pp
 invokes the

-.Cm SH
+.Ic SH

 macro when used in a
 .Xr man 7
 document.
 Such abuse is of course strongly discouraged.
 macro when used in a
 .Xr man 7
 document.
 Such abuse is of course strongly discouraged.

-.Ss \&ds1
+.It Ic \&ds1 Ar stringname Op Oo \(dq Oc Ns Ar string

 Define a user-defined string that will be expanded with
 .Nm
 compatibility mode switched off during string expansion.
 Define a user-defined string that will be expanded with
 .Nm
 compatibility mode switched off during string expansion.


@@ -811,228 +770,222 @@ Since
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for
 does not implement
 .Nm
 compatibility mode at all, it handles this request as an alias for

-.Sx \&ds .
-.Ss \&dwh
+.Ic \&ds .
+.It Ic \&dwh Ar dist macroname

 Set a location trap in the current diversion.
 This is a Heirloom extension and currently unsupported.
 Set a location trap in the current diversion.
 This is a Heirloom extension and currently unsupported.

-.Ss \&dt
+.It Ic \&dt Op Ar dist macroname

 Set a trap within a diversion.
 Currently unsupported.
 Set a trap within a diversion.
 Currently unsupported.

-.Ss \&ec
-Change the escape character.
-Currently unsupported.
-.Ss \&ecs
+.It Ic \&ec Op Ar char
+Enable the escape mechanism and change the escape character.
+The
+.Ar char
+argument defaults to the backslash
+.Pq Sq \e .
+.It Ic \&ecr

 Restore the escape character.
 Currently unsupported.
 Restore the escape character.
 Currently unsupported.

-.Ss \&ecr
+.It Ic \&ecs

 Save the escape character.
 Currently unsupported.
 Save the escape character.
 Currently unsupported.

-.Ss \&el
+.It Ic \&el Ar body

 The
 The

-.Qq else
+.Dq else

 half of an if/else conditional.
 Pops a result off the stack of conditional evaluations pushed by
 half of an if/else conditional.
 Pops a result off the stack of conditional evaluations pushed by

-.Sx \&ie
+.Ic \&ie

 and uses it as its conditional.
 If no stack entries are present (e.g., due to no prior
 and uses it as its conditional.
 If no stack entries are present (e.g., due to no prior

-.Sx \&ie
+.Ic \&ie

 calls)
 then false is assumed.
 The syntax of this request is similar to
 calls)
 then false is assumed.
 The syntax of this request is similar to

-.Sx \&if
+.Ic \&if

 except that the conditional is missing.
 except that the conditional is missing.

-.Ss \&em
+.It Ic \&em Ar macroname

 Set a trap at the end of input.
 Currently unsupported.
 Set a trap at the end of input.
 Currently unsupported.

-.Ss \&EN
+.It Ic \&EN

 End an equation block.
 See
 End an equation block.
 See

-.Sx \&EQ .
-.Ss \&eo
+.Ic \&EQ .
+.It Ic \&eo

 Disable the escape mechanism completely.
 Disable the escape mechanism completely.

-Currently unsupported.
-.Ss \&EP
+.It Ic \&EP

 End a picture started by
 End a picture started by

-.Sx \&BP .
+.Ic \&BP .

 This is a Heirloom extension and currently unsupported.
 This is a Heirloom extension and currently unsupported.

-.Ss \&EQ
+.It Ic \&EQ

 Begin an equation block.
 See
 .Xr eqn 7
 for a description of the equation language.
 Begin an equation block.
 See
 .Xr eqn 7
 for a description of the equation language.

-.Ss \&errprint
+.It Ic \&errprint Ar message

 Print a string like an error message.
 This is a Heirloom extension and currently ignored.
 Print a string like an error message.
 This is a Heirloom extension and currently ignored.

-.Ss \&ev
+.It Ic \&ev Op Ar envname

 Switch to another environment.
 Currently unsupported.
 Switch to another environment.
 Currently unsupported.

-.Ss \&evc
+.It Ic \&evc Op Ar envname

 Copy an environment into the current environment.
 Currently unsupported.
 Copy an environment into the current environment.
 Currently unsupported.

-.Ss \&ex
+.It Ic \&ex

 Abort processing and exit.
 Currently unsupported.
 Abort processing and exit.
 Currently unsupported.

-.Ss \&fallback
+.It Ic \&fallback Ar curfont font ...

 Select the fallback sequence for a font.
 This is a Heirloom extension and currently ignored.
 Select the fallback sequence for a font.
 This is a Heirloom extension and currently ignored.

-.Ss \&fam
+.It Ic \&fam Op Ar familyname

 Change the font family.
 Change the font family.

-Takes one argument specifying the font family to be selected.
-It is a groff extension and currently ignored.
-.Ss \&fc
+This is a groff extension and currently ignored.
+.It Ic \&fc Op Ar delimchar Op Ar padchar

 Define a delimiting and a padding character for fields.
 Currently unsupported.
 Define a delimiting and a padding character for fields.
 Currently unsupported.

-.Ss \&fchar
+.It Ic \&fchar Ar glyphname Op Ar string

 Define a fallback glyph.
 Currently unsupported.
 Define a fallback glyph.
 Currently unsupported.

-.Ss \&fcolor
+.It Ic \&fcolor Ar colorname

 Set the fill color for \eD objects.
 This is a groff extension and currently ignored.
 Set the fill color for \eD objects.
 This is a groff extension and currently ignored.

-.Ss \&fdeferlig
+.It Ic \&fdeferlig Ar font string ...

 Defer ligature building.
 This is a Heirloom extension and currently ignored.
 Defer ligature building.
 This is a Heirloom extension and currently ignored.

-.Ss \&feature
+.It Ic \&feature Cm + Ns | Ns Cm - Ns Ar name

 Enable or disable an OpenType feature.
 This is a Heirloom extension and currently ignored.
 Enable or disable an OpenType feature.
 This is a Heirloom extension and currently ignored.

-.Ss \&fi
+.It Ic \&fi

 Switch to fill mode.
 See
 .Xr man 7 .
 Ignored in
 .Xr mdoc 7 .
 Switch to fill mode.
 See
 .Xr man 7 .
 Ignored in
 .Xr mdoc 7 .

-.Ss \&fkern
+.It Ic \&fkern Ar font minkern

 Control the use of kerning tables for a font.
 This is a Heirloom extension and currently ignored.
 Control the use of kerning tables for a font.
 This is a Heirloom extension and currently ignored.

-.Ss \&fl
+.It Ic \&fl

 Flush output.
 Currently ignored.
 Flush output.
 Currently ignored.

-.Ss \&flig
+.It Ic \&flig Ar font string char ...

 Define ligatures.
 This is a Heirloom extension and currently ignored.
 Define ligatures.
 This is a Heirloom extension and currently ignored.

-.Ss \&fp
+.It Ic \&fp Ar position font Op Ar filename

 Assign font position.
 Currently ignored.
 Assign font position.
 Currently ignored.

-.Ss \&fps
+.It Ic \&fps Ar mapname ...

 Mount a font with a special character map.
 This is a Heirloom extension and currently ignored.
 Mount a font with a special character map.
 This is a Heirloom extension and currently ignored.

-.Ss \&fschar
+.It Ic \&fschar Ar font glyphname Op Ar string

 Define a font-specific fallback glyph.
 This is a groff extension and currently unsupported.
 Define a font-specific fallback glyph.
 This is a groff extension and currently unsupported.

-.Ss \&fspacewidth
+.It Ic \&fspacewidth Ar font Op Ar afmunits

 Set a font-specific width for the space character.
 This is a Heirloom extension and currently ignored.
 Set a font-specific width for the space character.
 This is a Heirloom extension and currently ignored.

-.Ss \&fspecial
+.It Ic \&fspecial Ar curfont Op Ar font ...

 Conditionally define a special font.
 This is a groff extension and currently ignored.
 Conditionally define a special font.
 This is a groff extension and currently ignored.

-.Ss \&ft
+.It Ic \&ft Op Ar font

 Change the font.
 Change the font.

-Its syntax is as follows:
-.Pp
-.D1 Pf . Cm \&ft Op Ar font
-.Pp

 The following
 .Ar font
 arguments are supported:
 .Bl -tag -width 4n -offset indent
 The following
 .Ar font
 arguments are supported:
 .Bl -tag -width 4n -offset indent

-.It Cm B , BI , 3 , 4
+.It Cm B , BI , CB , 3 , 4

 switches to
 .Sy bold
 font
 switches to
 .Sy bold
 font

-.It Cm I , 2
+.It Cm I , CI , 2

 switches to
 .Em underlined
 font
 switches to
 .Em underlined
 font

-.It Cm R , CW , 1
+.It Cm R , CR , CW , 1

 switches to normal font
 .It Cm P No "or no argument"
 switches back to the previous font
 .El
 .Pp
 switches to normal font
 .It Cm P No "or no argument"
 switches back to the previous font
 .El
 .Pp

-This request takes effect only locally, may be overridden by macros
-and escape sequences, and is only supported in
-.Xr man 7
-for now.
-.Ss \&ftr
+This request takes effect only locally and may be overridden
+by macros and escape sequences.
+.It Ic \&ftr Ar newname Op Ar oldname

 Translate font name.
 This is a groff extension and currently ignored.
 Translate font name.
 This is a groff extension and currently ignored.

-.Ss \&fzoom
+.It Ic \&fzoom Ar font Op Ar permille

 Zoom font size.
 Currently ignored.
 Zoom font size.
 Currently ignored.

-.Ss \&gcolor
+.It Ic \&gcolor Op Ar colorname

 Set glyph color.
 This is a groff extension and currently ignored.
 Set glyph color.
 This is a groff extension and currently ignored.

-.Ss \&hc
+.It Ic \&hc Op Ar char

 Set the hyphenation character.
 Currently ignored.
 Set the hyphenation character.
 Currently ignored.

-.Ss \&hcode
+.It Ic \&hcode Ar char code ...

 Set hyphenation codes of characters.
 Currently ignored.
 Set hyphenation codes of characters.
 Currently ignored.

-.Ss \&hidechar
+.It Ic \&hidechar Ar font char ...

 Hide characters in a font.
 This is a Heirloom extension and currently ignored.
 Hide characters in a font.
 This is a Heirloom extension and currently ignored.

-.Ss \&hla
+.It Ic \&hla Ar language

 Set hyphenation language.
 This is a groff extension and currently ignored.
 Set hyphenation language.
 This is a groff extension and currently ignored.

-.Ss \&hlm
+.It Ic \&hlm Op Ar number

 Set maximum number of consecutive hyphenated lines.
 Currently ignored.
 Set maximum number of consecutive hyphenated lines.
 Currently ignored.

-.Ss \&hpf
+.It Ic \&hpf Ar filename

 Load hyphenation pattern file.
 This is a groff extension and currently ignored.
 Load hyphenation pattern file.
 This is a groff extension and currently ignored.

-.Ss \&hpfa
+.It Ic \&hpfa Ar filename

 Load hyphenation pattern file, appending to the current patterns.
 This is a groff extension and currently ignored.
 Load hyphenation pattern file, appending to the current patterns.
 This is a groff extension and currently ignored.

-.Ss \&hpfcode
+.It Ic \&hpfcode Ar code code ...

 Define mapping values for character codes in hyphenation patterns.
 This is a groff extension and currently ignored.
 Define mapping values for character codes in hyphenation patterns.
 This is a groff extension and currently ignored.

-.Ss \&hw
+.It Ic \&hw Ar word ...

 Specify hyphenation points in words.
 Currently ignored.
 Specify hyphenation points in words.
 Currently ignored.

-.Ss \&hy
+.It Ic \&hy Op Ar mode

 Set automatic hyphenation mode.
 Currently ignored.
 Set automatic hyphenation mode.
 Currently ignored.

-.Ss \&hylang
+.It Ic \&hylang Ar language

 Set hyphenation language.
 This is a Heirloom extension and currently ignored.
 Set hyphenation language.
 This is a Heirloom extension and currently ignored.

-.Ss \&hylen
+.It Ic \&hylen Ar nchar

 Minimum word length for hyphenation.
 This is a Heirloom extension and currently ignored.
 Minimum word length for hyphenation.
 This is a Heirloom extension and currently ignored.

-.Ss \&hym
+.It Ic \&hym Op Ar length

 Set hyphenation margin.
 This is a groff extension and currently ignored.
 Set hyphenation margin.
 This is a groff extension and currently ignored.

-.Ss \&hypp
+.It Ic \&hypp Ar penalty ...

 Define hyphenation penalties.
 This is a Heirloom extension and currently ignored.
 Define hyphenation penalties.
 This is a Heirloom extension and currently ignored.

-.Ss \&hys
+.It Ic \&hys Op Ar length

 Set hyphenation space.
 This is a groff extension and currently ignored.
 Set hyphenation space.
 This is a groff extension and currently ignored.

-.Ss \&ie
+.It Ic \&ie Ar condition body

 The
 The

-.Qq if
+.Dq if

 half of an if/else conditional.
 The result of the conditional is pushed into a stack used by subsequent
 invocations of
 half of an if/else conditional.
 The result of the conditional is pushed into a stack used by subsequent
 invocations of

-.Sx \&el ,
+.Ic \&el ,

 which may be separated by any intervening input (or not exist at all).
 Its syntax is equivalent to
 which may be separated by any intervening input (or not exist at all).
 Its syntax is equivalent to

-.Sx \&if .
-.Ss \&if
-Begins a conditional.
-This request has the following syntax:
-.Bd -literal -offset indent
-\&.if COND BODY
-.Ed
-.Bd -literal -offset indent
-\&.if COND \e{BODY
-BODY...\e}
+.Ic \&if .
+.It Ic \&if Ar condition body
+Begin a conditional.
+This request can also be written as follows:
+.Bd -unfilled -offset indent
+.Pf . Ic \&if Ar condition No \e{ Ns Ar body
+.Ar body ... Ns \e}

 .Ed
 .Ed

-.Bd -literal -offset indent
-\&.if COND \e{\e
-BODY...
-\&.\e}
+.Bd -unfilled -offset indent
+.Pf . Ic \&if Ar condition No \e{\e
+.Ar body ...
+.Pf . No \e}

 .Ed
 .Pp
 .Ed
 .Pp

-COND is a conditional statement.
+The
+.Ar condition
+is a boolean expression.

 Currently,
 .Xr mandoc 1
 supports the following subset of roff conditionals:
 Currently,
 .Xr mandoc 1
 supports the following subset of roff conditionals:


@@ -1040,45 +993,83 @@ supports the following subset of roff conditionals:
 .It
 If
 .Sq \&!
 .It
 If
 .Sq \&!

-is prefixed to COND, the condition is logically inverted.
+is prefixed to
+.Ar condition ,
+it is logically inverted.

 .It
 .It

-If the first character of COND is
+If the first character of
+.Ar condition
+is

 .Sq n
 .Pq nroff mode
 or
 .Sq o
 .Pq odd page ,
 .Sq n
 .Pq nroff mode
 or
 .Sq o
 .Pq odd page ,

-COND evaluates to true.
+it evaluates to true, and the
+.Ar body
+starts with the next character.

 .It
 .It

-If the first character of COND is
-.Sq c
-.Pq character available ,
-.Sq d
-.Pq string defined ,
+If the first character of
+.Ar condition
+is

 .Sq e
 .Pq even page ,
 .Sq e
 .Pq even page ,

-.Sq r
-.Pq register accessed ,

 .Sq t
 .Pq troff mode ,
 or
 .Sq v
 .Pq vroff mode ,
 .Sq t
 .Pq troff mode ,
 or
 .Sq v
 .Pq vroff mode ,

-COND evaluates to false.
+it evaluates to false, and the
+.Ar body
+starts with the next character.
+.It
+If the first character of
+.Ar condition
+is
+.Sq c
+.Pq character available ,
+it evaluates to true if the following character is an ASCII character
+or a valid character escape sequence, or to false otherwise.
+The
+.Ar body
+starts with the character following that next character.

 .It
 .It

-If COND starts with a parenthesis or with an optionally signed
+If the first character of
+.Ar condition
+is
+.Sq d ,
+it evaluates to true if the rest of
+.Ar condition
+is the name of an existing user defined macro or string;
+otherwise, it evaluates to false.
+.It
+If the first character of
+.Ar condition
+is
+.Sq r ,
+it evaluates to true if the rest of
+.Ar condition
+is the name of an existing number register;
+otherwise, it evaluates to false.
+.It
+If the
+.Ar condition
+starts with a parenthesis or with an optionally signed

 integer number, it is evaluated according to the rules of
 .Sx Numerical expressions
 explained below.
 It evaluates to true if the result is positive,
 or to false if the result is zero or negative.
 .It
 integer number, it is evaluated according to the rules of
 .Sx Numerical expressions
 explained below.
 It evaluates to true if the result is positive,
 or to false if the result is zero or negative.
 .It

-Otherwise, the first character of COND is regarded as a delimiter
-and COND evaluates to true if the string extending from its first
-to its second occurrence is equal to the string extending from its
-second to its third occurrence.
+Otherwise, the first character of
+.Ar condition
+is regarded as a delimiter and it evaluates to true if the string
+extending from its first to its second occurrence is equal to the
+string extending from its second to its third occurrence.

 .It
 .It

-If COND cannot be parsed, it evaluates to false.
+If
+.Ar condition
+cannot be parsed, it evaluates to false.

 .El
 .Pp
 If a conditional is false, its children are not processed, but are
 .El
 .Pp
 If a conditional is false, its children are not processed, but are


@@ -1099,28 +1090,33 @@ conditional.
 Sub-conditionals, in this case, obviously inherit the truth value of
 the parent.
 .Pp
 Sub-conditionals, in this case, obviously inherit the truth value of
 the parent.
 .Pp

-If the BODY section is begun by an escaped brace
+If the
+.Ar body
+section is begun by an escaped brace

 .Sq \e{ ,
 scope continues until the end of the input line containing the
 matching closing-brace escape sequence
 .Sq \e} .
 .Sq \e{ ,
 scope continues until the end of the input line containing the
 matching closing-brace escape sequence
 .Sq \e} .

-If the BODY is not enclosed in braces, scope continues until
-the end of the line.
-If the COND is followed by a BODY on the same line, whether after a
-brace or not, then requests and macros
+If the
+.Ar body
+is not enclosed in braces, scope continues until the end of the line.
+If the
+.Ar condition
+is followed by a
+.Ar body
+on the same line, whether after a brace or not, then requests and macros

 .Em must
 begin with a control character.
 It is generally more intuitive, in this case, to write
 .Em must
 begin with a control character.
 It is generally more intuitive, in this case, to write

-.Bd -literal -offset indent
-\&.if COND \e{\e
-\&.foo
-bar
-\&.\e}
+.Bd -unfilled -offset indent
+.Pf . Ic \&if Ar condition No \e{\e
+.Pf . Ar request
+.Pf . No \e}

 .Ed
 .Pp
 than having the request or macro follow as
 .Pp
 .Ed
 .Pp
 than having the request or macro follow as
 .Pp

-.D1 \&.if COND \e{ .foo
+.D1 Pf . Ic \&if Ar condition Pf \e{. Ar request

 .Pp
 The scope of a conditional is always parsed, but only executed if the
 conditional evaluates to true.
 .Pp
 The scope of a conditional is always parsed, but only executed if the
 conditional evaluates to true.


@@ -1139,7 +1135,7 @@ will result in
 being considered an argument of the
 .Sq \&Fl
 macro.
 being considered an argument of the
 .Sq \&Fl
 macro.

-.Ss \&ig
+.It Ic \&ig Op Ar endmacro

 Ignore input.
 Its syntax can be either
 .Bd -literal -offset indent
 Ignore input.
 Its syntax can be either
 .Bd -literal -offset indent


@@ -1150,31 +1146,31 @@ Its syntax can be either
 .Pp
 or
 .Bd -literal -offset indent
 .Pp
 or
 .Bd -literal -offset indent

-.Pf . Cm \&ig Ar end
+.Pf . Cm \&ig Ar endmacro

 .Ar ignored text
 .Ar ignored text

-.Pf . Ar end
+.Pf . Ar endmacro

 .Ed
 .Pp
 In the first case, input is ignored until a
 .Sq \&..
 request is encountered on its own line.
 In the second case, input is ignored until the specified
 .Ed
 .Pp
 In the first case, input is ignored until a
 .Sq \&..
 request is encountered on its own line.
 In the second case, input is ignored until the specified

-.Sq Pf . Ar end
-macro is encountered.
+.Sq Pf . Ar endmacro
+is encountered.

 Do not use the escape character
 .Sq \e
 anywhere in the definition of
 Do not use the escape character
 .Sq \e
 anywhere in the definition of

-.Ar end ;
+.Ar endmacro ;

 it would cause very strange behaviour.
 .Pp
 When the
 it would cause very strange behaviour.
 .Pp
 When the

-.Ar end
-macro is a roff request or a roff macro, like in
+.Ar endmacro
+is a roff request or a roff macro, like in

 .Pp
 .D1 \&.ig if
 .Pp
 the subsequent invocation of
 .Pp
 .D1 \&.ig if
 .Pp
 the subsequent invocation of

-.Sx \&if
+.Ic \&if

 will first terminate the
 .Ar ignored text ,
 then be invoked as usual.
 will first terminate the
 .Ar ignored text ,
 then be invoked as usual.


@@ -1183,83 +1179,80 @@ Otherwise, it only terminates the
 and arguments following it or the
 .Sq \&..
 request are discarded.
 and arguments following it or the
 .Sq \&..
 request are discarded.

-.Ss \&in
+.It Ic \&in Op Oo Cm + Ns | Ns Cm - Oc Ns Ar width

 Change indentation.
 See
 .Xr man 7 .
 Ignored in
 .Xr mdoc 7 .
 Change indentation.
 See
 .Xr man 7 .
 Ignored in
 .Xr mdoc 7 .

-.Ss \&index
+.It Ic \&index Ar register stringname substring

 Find a substring in a string.
 This is a Heirloom extension and currently unsupported.
 Find a substring in a string.
 This is a Heirloom extension and currently unsupported.

-.Ss \&it
+.It Ic \&it Ar expression macro

 Set an input line trap.
 Set an input line trap.

-Its syntax is as follows:
-.Pp
-.D1 Pf . Cm it Ar number macro
-.Pp

 The named
 .Ar macro
 The named
 .Ar macro

-will be invoked after processing the specified
-.Ar number
-of input text lines.
-.Ss \&itc
+will be invoked after processing the number of input text lines
+specified by the numerical
+.Ar expression .
+While evaluating the
+.Ar expression ,
+the unit suffixes described below
+.Sx Scaling Widths
+are ignored.
+.It Ic \&it Ar expression macro

 Set an input line trap, not counting lines ending with \ec.
 Currently unsupported.
 Set an input line trap, not counting lines ending with \ec.
 Currently unsupported.

-.Ss \&IX
+.It Ic \&IX Ar class keystring

 To support the generation of a table of contents,
 .Xr pod2man 1
 emits this user-defined macro, usually without defining it.
 To avoid reporting large numbers of spurious errors,
 .Xr mandoc 1
 ignores it.
 To support the generation of a table of contents,
 .Xr pod2man 1
 emits this user-defined macro, usually without defining it.
 To avoid reporting large numbers of spurious errors,
 .Xr mandoc 1
 ignores it.

-.Ss \&kern
+.It Ic \&kern Op Cm 1 | 0

 Switch kerning on or off.
 Currently ignored.
 Switch kerning on or off.
 Currently ignored.

-.Ss \&kernafter
+.It Ic \&kernafter Ar font char ... afmunits ...

 Increase kerning after some characters.
 This is a Heirloom extension and currently ignored.
 Increase kerning after some characters.
 This is a Heirloom extension and currently ignored.

-.Ss \&kernbefore
+.It Ic \&kernbefore Ar font char ... afmunits ...

 Increase kerning before some characters.
 This is a Heirloom extension and currently ignored.
 Increase kerning before some characters.
 This is a Heirloom extension and currently ignored.

-.Ss \&kernpair
+.It Ic \&kernpair Ar font char ... font char ... afmunits

 Add a kerning pair to the kerning table.
 This is a Heirloom extension and currently ignored.
 Add a kerning pair to the kerning table.
 This is a Heirloom extension and currently ignored.

-.Ss \&lc
+.It Ic \&lc Op Ar glyph

 Define a leader repetition character.
 Currently unsupported.
 Define a leader repetition character.
 Currently unsupported.

-.Ss \&lc_ctype
+.It Ic \&lc_ctype Ar localename

 Set the
 .Dv LC_CTYPE
 locale.
 This is a Heirloom extension and currently unsupported.
 Set the
 .Dv LC_CTYPE
 locale.
 This is a Heirloom extension and currently unsupported.

-.Ss \&lds
+.It Ic \&lds Ar macroname string

 Define a local string.
 This is a Heirloom extension and currently unsupported.
 Define a local string.
 This is a Heirloom extension and currently unsupported.

-.Ss \&length
-Count the number of input characters in a user-defined string.
+.It Ic \&length Ar register string
+Count the number of input characters in a string.

 Currently unsupported.
 Currently unsupported.

-.Ss \&letadj
+.It Ic \&letadj Ar lspmin lshmin letss lspmax lshmax

 Dynamic letter spacing and reshaping.
 This is a Heirloom extension and currently ignored.
 Dynamic letter spacing and reshaping.
 This is a Heirloom extension and currently ignored.

-.Ss \&lf
+.It Ic \&lf Ar lineno Op Ar filename

 Change the line number for error messages.
 Ignored because insecure.
 Change the line number for error messages.
 Ignored because insecure.

-.Ss \&lg
+.It Ic \&lg Op Cm 1 | 0

 Switch the ligature mechanism on or off.
 Currently ignored.
 Switch the ligature mechanism on or off.
 Currently ignored.

-.Ss \&lhang
+.It Ic \&lhang Ar font char ... afmunits

 Hang characters at left margin.
 This is a Heirloom extension and currently ignored.
 Hang characters at left margin.
 This is a Heirloom extension and currently ignored.

-.Ss \&linetabs
+.It Ic \&linetabs Op Cm 1 | 0

 Enable or disable line-tabs mode.
 This is a groff extension and currently unsupported.
 Enable or disable line-tabs mode.
 This is a groff extension and currently unsupported.

-.Ss \&ll
+.It Ic \&ll Op Oo Cm + Ns | Ns Cm - Oc Ns Ar width

 Change the output line length.
 Change the output line length.

-Its syntax is as follows:
-.Pp
-.D1 Pf . Cm \&ll Op Oo +|- Oc Ns Ar width
-.Pp

 If the
 .Ar width
 argument is omitted, the line length is reset to its previous value.
 If the
 .Ar width
 argument is omitted, the line length is reset to its previous value.


@@ -1271,77 +1264,78 @@ among others because it overrides the
 .Xr mandoc 1
 .Fl O Cm width
 command line option.
 .Xr mandoc 1
 .Fl O Cm width
 command line option.

-.Ss \&lnr
+.It Ic \&lnr Ar register Oo Cm + Ns | Ns Cm - Oc Ns Ar value Op Ar increment

 Set local number register.
 This is a Heirloom extension and currently unsupported.
 Set local number register.
 This is a Heirloom extension and currently unsupported.

-.Ss \&lnrf
+.It Ic \&lnrf Ar register Oo Cm + Ns | Ns Cm - Oc Ns Ar value Op Ar increment

 Set local floating-point register.
 This is a Heirloom extension and currently unsupported.
 Set local floating-point register.
 This is a Heirloom extension and currently unsupported.

-.Ss \&lpfx
+.It Ic \&lpfx Ar string

 Set a line prefix.
 This is a Heirloom extension and currently unsupported.
 Set a line prefix.
 This is a Heirloom extension and currently unsupported.

-.Ss \&ls
+.It Ic \&ls Op Ar factor

 Set line spacing.
 It takes one integer argument specifying the vertical distance of
 subsequent output text lines measured in v units.
 Currently ignored.
 Set line spacing.
 It takes one integer argument specifying the vertical distance of
 subsequent output text lines measured in v units.
 Currently ignored.

-.Ss \&lsm
+.It Ic \&lsm Ar macroname

 Set a leading spaces trap.
 This is a groff extension and currently unsupported.
 Set a leading spaces trap.
 This is a groff extension and currently unsupported.

-.Ss \&lt
+.It Ic \&lt Op Oo Cm + Ns | Ns Cm - Oc Ns Ar width

 Set title line length.
 Currently ignored.
 Set title line length.
 Currently ignored.

-.Ss \&mc
+.It Ic \&mc Ar glyph Op Ar dist

 Print margin character in the right margin.
 Print margin character in the right margin.

-Currently ignored.
-.Ss \&mediasize
+The
+.Ar dist
+is currently ignored; instead, 1n is used.
+.It Ic \&mediasize Ar media

 Set the device media size.
 This is a Heirloom extension and currently ignored.
 Set the device media size.
 This is a Heirloom extension and currently ignored.

-.Ss \&minss
+.It Ic \&minss Ar width

 Set minimum word space.
 This is a Heirloom extension and currently ignored.
 Set minimum word space.
 This is a Heirloom extension and currently ignored.

-.Ss \&mk
+.It Ic \&mk Op Ar register

 Mark vertical position.
 Currently ignored.
 Mark vertical position.
 Currently ignored.

-.Ss \&mso
-Load a macro file.
+.It Ic \&mso Ar filename
+Load a macro file using the search path.

 Ignored because insecure.
 Ignored because insecure.

-.Ss \&na
+.It Ic \&na

 Disable adjusting without changing the adjustment mode.
 Currently ignored.
 Disable adjusting without changing the adjustment mode.
 Currently ignored.

-.Ss \&ne
+.It Ic \&ne Op Ar height

 Declare the need for the specified minimum vertical space
 before the next trap or the bottom of the page.
 Currently ignored.
 Declare the need for the specified minimum vertical space
 before the next trap or the bottom of the page.
 Currently ignored.

-.Ss \&nf
+.It Ic \&nf

 Switch to no-fill mode.
 See
 .Xr man 7 .
 Ignored by
 .Xr mdoc 7 .
 Switch to no-fill mode.
 See
 .Xr man 7 .
 Ignored by
 .Xr mdoc 7 .

-.Ss \&nh
+.It Ic \&nh

 Turn off automatic hyphenation mode.
 Currently ignored.
 Turn off automatic hyphenation mode.
 Currently ignored.

-.Ss \&nhychar
+.It Ic \&nhychar Ar char ...

 Define hyphenation-inhibiting characters.
 This is a Heirloom extension and currently ignored.
 Define hyphenation-inhibiting characters.
 This is a Heirloom extension and currently ignored.

-.Ss \&nm
+.It Ic \&nm Op Ar start Op Ar inc Op Ar space Op Ar indent

 Print line numbers.
 Currently unsupported.
 Print line numbers.
 Currently unsupported.

-.Ss \&nn
+.It Ic \&nn Op Ar number

 Temporarily turn off line numbering.
 Currently unsupported.
 Temporarily turn off line numbering.
 Currently unsupported.

-.Ss \&nop
-Exexute the rest of the input line as a request or macro line.
-Currently unsupported.
-.Ss \&nr
+.It Ic \&nop Ar body
+Execute the rest of the input line as a request, macro, or text line,
+skipping the
+.Ic \&nop
+request and any space characters immediately following it.
+This is mostly used to indent text lines inside macro definitions.
+.It Ic \&nr Ar register Oo Cm + Ns | Ns Cm - Oc Ns Ar expression Op Ar stepsize

 Define or change a register.
 A register is an arbitrary string value that defines some sort of state,
 which influences parsing and/or formatting.
 Define or change a register.
 A register is an arbitrary string value that defines some sort of state,
 which influences parsing and/or formatting.

-Its syntax is as follows:
-.Pp
-.D1 Pf \. Cm \&nr Ar name Oo +|- Oc Ns Ar expression
-.Pp

 For the syntax of
 .Ar expression ,
 see
 For the syntax of
 .Ar expression ,
 see


@@ -1350,8 +1344,16 @@ below.
 If it is prefixed by a sign, the register will be
 incremented or decremented instead of assigned to.
 .Pp
 If it is prefixed by a sign, the register will be
 incremented or decremented instead of assigned to.
 .Pp

-The following register
-.Ar name
+The
+.Ar stepsize
+is used by the
+.Ic \en+
+auto-increment feature.
+It remains unchanged when omitted while changing an existing register,
+and it defaults to 0 when defining a new register.
+.Pp
+The following
+.Ar register

 is handled specially:
 .Bl -tag -width Ds
 .It Cm nS
 is handled specially:
 .Bl -tag -width Ds
 .It Cm nS


@@ -1368,155 +1370,165 @@ section itself.
 Note that starting a new
 .Xr mdoc 7
 section with the
 Note that starting a new
 .Xr mdoc 7
 section with the

-.Cm \&Sh
+.Ic \&Sh

 macro will reset this register.
 .El
 macro will reset this register.
 .El

-.Ss \&nrf
+.It Xo
+.Ic \&nrf Ar register Oo Cm + Ns | Ns Cm - Oc Ns Ar expression
+.Op Ar increment
+.Xc

 Define or change a floating-point register.
 This is a Heirloom extension and currently unsupported.
 Define or change a floating-point register.
 This is a Heirloom extension and currently unsupported.

-.Ss \&nroff
+.It Ic \&nroff

 Force nroff mode.
 This is a groff extension and currently ignored.
 Force nroff mode.
 This is a groff extension and currently ignored.

-.Ss \&ns
+.It Ic \&ns

 Turn on no-space mode.
 Currently ignored.
 Turn on no-space mode.
 Currently ignored.

-.Ss \&nx
+.It Ic \&nx Op Ar filename

 Abort processing of the current input file and process another one.
 Ignored because insecure.
 Abort processing of the current input file and process another one.
 Ignored because insecure.

-.Ss \&open
+.It Ic \&open Ar stream file

 Open a file for writing.
 Ignored because insecure.
 Open a file for writing.
 Ignored because insecure.

-.Ss \&opena
+.It Ic \&opena Ar stream file

 Open a file for appending.
 Ignored because insecure.
 Open a file for appending.
 Ignored because insecure.

-.Ss \&os
+.It Ic \&os

 Output saved vertical space.
 Currently ignored.
 Output saved vertical space.
 Currently ignored.

-.Ss \&output
+.It Ic \&output Ar string

 Output directly to intermediate output.
 Not supported.
 Output directly to intermediate output.
 Not supported.

-.Ss \&padj
+.It Ic \&padj Op Cm 1 | 0

 Globally control paragraph-at-once adjustment.
 This is a Heirloom extension and currently ignored.
 Globally control paragraph-at-once adjustment.
 This is a Heirloom extension and currently ignored.

-.Ss \&papersize
+.It Ic \&papersize Ar media

 Set the paper size.
 This is a Heirloom extension and currently ignored.
 Set the paper size.
 This is a Heirloom extension and currently ignored.

-.Ss \&pc
+.It Ic \&pc Op Ar char

 Change the page number character.
 Currently ignored.
 Change the page number character.
 Currently ignored.

-.Ss \&pev
+.It Ic \&pev

 Print environments.
 This is a groff extension and currently ignored.
 Print environments.
 This is a groff extension and currently ignored.

-.Ss \&pi
+.It Ic \&pi Ar command

 Pipe output to a shell command.
 Ignored because insecure.
 Pipe output to a shell command.
 Ignored because insecure.

-.Ss \&PI
+.It Ic \&PI

 Low-level request used by
 Low-level request used by

-.Sx \&BP .
+.Ic \&BP .

 This is a Heirloom extension and currently unsupported.
 This is a Heirloom extension and currently unsupported.

-.Ss \&pl
+.It Ic \&pl Op Oo Cm + Ns | Ns Cm - Oc Ns Ar height

 Change page length.
 Change page length.

-Takes one height argument.

 Currently ignored.
 Currently ignored.

-.Ss \&pm
-Print names and sizes of macros, strings, and diversions.
+.It Ic \&pm
+Print names and sizes of macros, strings, and diversions
+to standard error output.

 Currently ignored.
 Currently ignored.

-.Ss \&pn
-Change page number of the next page.
+.It Ic \&pn Oo Cm + Ns | Ns Cm - Oc Ns Ar number
+Change the page number of the next page.

 Currently ignored.
 Currently ignored.

-.Ss \&pnr
-Print all number registers.
+.It Ic \&pnr
+Print all number registers on standard error output.

 Currently ignored.
 Currently ignored.

-.Ss \&po
-Set horizontal page offset.
-Currently ignored.
-.Ss \&ps
+.It Ic \&po Op Oo Cm + Ns | Ns Cm - Oc Ns Ar offset
+Set a horizontal page offset.
+If no argument is specified, the page offset is reverted to its
+previous value.
+If a sign is specified, the new page offset is calculated relative
+to the current one; otherwise, it is absolute.
+The argument follows the syntax of
+.Sx Scaling Widths
+and the default scaling unit is
+.Cm m .
+.It Ic \&ps Op Oo Cm + Ns | Ns Cm - Oc Ns size

 Change point size.
 Change point size.

-Takes one numerical argument.

 Currently ignored.
 Currently ignored.

-.Ss \&psbb
+.It Ic \&psbb Ar filename

 Retrieve the bounding box of a PostScript file.
 Currently unsupported.
 Retrieve the bounding box of a PostScript file.
 Currently unsupported.

-.Ss \&pshape
+.It Ic \&pshape Ar indent length ...

 Set a special shape for the current paragraph.
 Set a special shape for the current paragraph.

-This is a Heirloom extension and currently ignored.
-.Ss \&pso
+This is a Heirloom extension and currently unsupported.
+.It Ic \&pso Ar command

 Include output of a shell command.
 Ignored because insecure.
 Include output of a shell command.
 Ignored because insecure.

-.Ss \&ptr
-Print the names and positions of all traps.
+.It Ic \&ptr
+Print the names and positions of all traps on standard error output.

 This is a groff extension and currently ignored.
 This is a groff extension and currently ignored.

-.Ss \&pvs
+.It Ic \&pvs Op Oo Cm + Ns | Ns Cm - Oc Ns Ar height

 Change post-vertical spacing.
 This is a groff extension and currently ignored.
 Change post-vertical spacing.
 This is a groff extension and currently ignored.

-.Ss \&rchar
+.It Ic \&rchar Ar glyph ...

 Remove glyph definitions.
 Currently unsupported.
 Remove glyph definitions.
 Currently unsupported.

-.Ss \&rd
+.It Ic \&rd Op Ar prompt Op Ar argument ...

 Read from standard input.
 Currently ignored.
 Read from standard input.
 Currently ignored.

-.Ss \&recursionlimit
+.It Ic \&recursionlimit Ar maxrec maxtail

 Set the maximum stack depth for recursive macros.
 This is a Heirloom extension and currently ignored.
 Set the maximum stack depth for recursive macros.
 This is a Heirloom extension and currently ignored.

-.Ss \&return
+.It Ic \&return Op Ar twice

 Exit a macro and return to the caller.
 Currently unsupported.
 Exit a macro and return to the caller.
 Currently unsupported.

-.Ss \&rfschar
+.It Ic \&rfschar Ar font glyph ...

 Remove font-specific fallback glyph definitions.
 Currently unsupported.
 Remove font-specific fallback glyph definitions.
 Currently unsupported.

-.Ss \&rhang
+.It Ic \&rhang Ar font char ... afmunits

 Hang characters at right margin.
 This is a Heirloom extension and currently ignored.
 Hang characters at right margin.
 This is a Heirloom extension and currently ignored.

-.Ss \&rj
-Justify unfilled text to the right margin.
-Currently ignored.
-.Ss \&rm
+.It Ic \&rj Op Ar N
+Justify the next
+.Ar N
+input lines to the right margin without filling.
+.Ar N
+defaults to 1.
+An argument of 0 or less ends right adjustment.
+.It Ic \&rm Ar macroname

 Remove a request, macro or string.
 Remove a request, macro or string.

-Its syntax is as follows:
-.Pp
-.D1 Pf \. Cm \&rm Ar name
-.Ss \&rn
+.It Ic \&rn Ar oldname newname

 Rename a request, macro, diversion, or string.
 Rename a request, macro, diversion, or string.

-Currently unsupported.
-.Ss \&rnn
+In
+.Xr mandoc 1 ,
+user-defined macros,
+.Xr mdoc 7
+and
+.Xr man 7
+macros, and user-defined strings can be renamed, but renaming of
+predefined strings and of
+.Nm
+requests is not supported, and diversions are not implemented at all.
+.It Ic \&rnn Ar oldname newname

 Rename a number register.
 Currently unsupported.
 Rename a number register.
 Currently unsupported.

-.Ss \&rr
+.It Ic \&rr Ar register

 Remove a register.
 Remove a register.

-Its syntax is as follows:
-.Pp
-.D1 Pf \. Cm \&rr Ar name
-.Ss \&rs
+.It Ic \&rs

 End no-space mode.
 Currently ignored.
 End no-space mode.
 Currently ignored.

-.Ss \&rt
+.It Ic \&rt Op Ar dist

 Return to marked vertical position.
 Currently ignored.
 Return to marked vertical position.
 Currently ignored.

-.Ss \&schar
+.It Ic \&schar Ar glyph Op Ar string

 Define global fallback glyph.
 This is a groff extension and currently unsupported.
 Define global fallback glyph.
 This is a groff extension and currently unsupported.

-.Ss \&sentchar
+.It Ic \&sentchar Ar char ...

 Define sentence-ending characters.
 This is a Heirloom extension and currently ignored.
 Define sentence-ending characters.
 This is a Heirloom extension and currently ignored.

-.Ss \&shc
+.It Ic \&shc Op Ar glyph

 Change the soft hyphen character.
 Currently ignored.
 Change the soft hyphen character.
 Currently ignored.

-.Ss \&shift
+.It Ic \&shift Op Ar number

 Shift macro arguments.
 Currently unsupported.
 Shift macro arguments.
 Currently unsupported.

-.Ss \&sizes
+.It Ic \&sizes Ar size ...

 Define permissible point sizes.
 This is a groff extension and currently ignored.
 Define permissible point sizes.
 This is a groff extension and currently ignored.

-.Ss \&so
+.It Ic \&so Ar filename

 Include a source file.
 Include a source file.

-Its syntax is as follows:
-.Pp
-.D1 Pf \. Cm \&so Ar file
-.Pp
-The
-.Ar file
-will be read and its contents processed as input in place of the
-.Sq \&.so
+The file is read and its contents processed as input in place of the
+.Ic \&so

 request line.
 To avoid inadvertent inclusion of unrelated files,
 .Xr mandoc 1
 request line.
 To avoid inadvertent inclusion of unrelated files,
 .Xr mandoc 1


@@ -1535,168 +1547,184 @@ Typical usage looks like:
 .Dl \&.so man3/Xcursor.3
 .Pp
 As the whole concept is rather fragile, the use of
 .Dl \&.so man3/Xcursor.3
 .Pp
 As the whole concept is rather fragile, the use of

-.Sx \&so
+.Ic \&so

 is discouraged.
 Use
 .Xr ln 1
 instead.
 is discouraged.
 Use
 .Xr ln 1
 instead.

-.Ss \&spacewidth
+.It Ic \&sp Op Ar height
+Break the output line and emit vertical space.
+The argument follows the syntax of
+.Sx Scaling Widths
+and defaults to one blank line
+.Pq Li 1v .
+.It Ic \&spacewidth Op Cm 1 | 0

 Set the space width from the font metrics file.
 This is a Heirloom extension and currently ignored.
 Set the space width from the font metrics file.
 This is a Heirloom extension and currently ignored.

-.Ss \&special
+.It Ic \&special Op Ar font ...

 Define a special font.
 This is a groff extension and currently ignored.
 Define a special font.
 This is a groff extension and currently ignored.

-.Ss \&spreadwarn
+.It Ic \&spreadwarn Op Ar width

 Warn about wide spacing between words.
 Currently ignored.
 Warn about wide spacing between words.
 Currently ignored.

-.Ss \&ss
+.It Ic \&ss Ar wordspace Op Ar sentencespace

 Set space character size.
 Currently ignored.
 Set space character size.
 Currently ignored.

-.Ss \&sty
+.It Ic \&sty Ar position style

 Associate style with a font position.
 This is a groff extension and currently ignored.
 Associate style with a font position.
 This is a groff extension and currently ignored.

-.Ss \&substring
+.It Ic \&substring Ar stringname startpos Op Ar endpos

 Replace a user-defined string with a substring.
 Currently unsupported.
 Replace a user-defined string with a substring.
 Currently unsupported.

-.Ss \&sv
+.It Ic \&sv Op Ar height

 Save vertical space.
 Currently ignored.
 Save vertical space.
 Currently ignored.

-.Ss \&sy
+.It Ic \&sy Ar command

 Execute shell command.
 Ignored because insecure.
 Execute shell command.
 Ignored because insecure.

-.Ss \&T&
+.It Ic \&T&

 Re-start a table layout, retaining the options of the prior table
 invocation.
 See
 .Sx \&TS .
 Re-start a table layout, retaining the options of the prior table
 invocation.
 See
 .Sx \&TS .

-.Ss \&ta
+.It Ic \&ta Op Ar width ... Op Cm T Ar width ...

 Set tab stops.
 Set tab stops.

-Takes an arbitrary number of arguments.
-Currently ignored.
-.Ss \&tc
-Change tab repetion character.
+Each
+.Ar width
+argument follows the syntax of
+.Sx Scaling Widths .
+If prefixed by a plus sign, it is relative to the previous tab stop.
+The arguments after the
+.Cm T
+marker are used repeatedly as often as needed; for each reuse,
+they are taken relative to the last previously established tab stop.
+When
+.Ic \&ta
+is called without arguments, all tab stops are cleared.
+.It Ic \&tc Op Ar glyph
+Change tab repetition character.

 Currently unsupported.
 Currently unsupported.

-.Ss \&TE
+.It Ic \&TE

 End a table context.
 See
 .Sx \&TS .
 End a table context.
 See
 .Sx \&TS .

-.Ss \&ti
-Temporary indent.
-Currently ignored.
-.Ss \&tkf
+.It Ic \&ti Oo Cm + Ns | Ns Cm - Oc Ns Ar width
+Break the output line and indent the next output line by
+.Ar width .
+If a sign is specified, the temporary indentation is calculated
+relative to the current indentation; otherwise, it is absolute.
+The argument follows the syntax of
+.Sx Scaling Widths
+and the default scaling unit is
+.Cm m .
+.It Ic \&tkf Ar font minps width1 maxps width2

 Enable track kerning for a font.
 Currently ignored.
 Enable track kerning for a font.
 Currently ignored.

-.Ss \&tl
+.It Ic \&tl No \& Ap Ar left Ap Ar center Ap Ar right Ap

 Print a title line.
 Currently unsupported.
 Print a title line.
 Currently unsupported.

-.Ss \&tm
+.It Ic \&tm Ar string

 Print to standard error output.
 Currently ignored.
 Print to standard error output.
 Currently ignored.

-.Ss \&tm1
+.It Ic \&tm1 Ar string

 Print to standard error output, allowing leading blanks.
 This is a groff extension and currently ignored.
 Print to standard error output, allowing leading blanks.
 This is a groff extension and currently ignored.

-.Ss \&tmc
+.It Ic \&tmc Ar string

 Print to standard error output without a trailing newline.
 This is a groff extension and currently ignored.
 Print to standard error output without a trailing newline.
 This is a groff extension and currently ignored.

-.Ss \&tr
+.It Ic \&tr Ar glyph glyph ...

 Output character translation.
 Output character translation.

-Its syntax is as follows:
-.Pp
-.D1 Pf \. Cm \&tr Ar [ab]+
-.Pp
-Pairs of
-.Ar ab
-characters are replaced
-.Ar ( a
-for
-.Ar b ) .
-Replacement (or origin) characters may also be character escapes; thus,
+The first glyph in each pair is replaced by the second one.
+Character escapes can be used; for example,

 .Pp
 .Dl tr \e(xx\e(yy
 .Pp
 replaces all invocations of \e(xx with \e(yy.
 .Pp
 .Dl tr \e(xx\e(yy
 .Pp
 replaces all invocations of \e(xx with \e(yy.

-.Ss \&track
+.It Ic \&track Ar font minps width1 maxps width2

 Static letter space tracking.
 This is a Heirloom extension and currently ignored.
 Static letter space tracking.
 This is a Heirloom extension and currently ignored.

-.Ss \&transchar
+.It Ic \&transchar Ar char ...

 Define transparent characters for sentence-ending.
 This is a Heirloom extension and currently ignored.
 Define transparent characters for sentence-ending.
 This is a Heirloom extension and currently ignored.

-.Ss \&trf
+.It Ic \&trf Ar filename

 Output the contents of a file, disallowing invalid characters.
 This is a groff extension and ignored because insecure.
 Output the contents of a file, disallowing invalid characters.
 This is a groff extension and ignored because insecure.

-.Ss \&trimat
+.It Ic \&trimat Ar left top width height

 Set the TrimBox page parameter for PDF generation.
 This is a Heirloom extension and currently ignored.
 Set the TrimBox page parameter for PDF generation.
 This is a Heirloom extension and currently ignored.

-.Ss \&trin
+.It Ic \&trin Ar glyph glyph ...

 Output character translation, ignored by
 Output character translation, ignored by

-.Cm \&asciify .
+.Ic \&asciify .

 Currently unsupported.
 Currently unsupported.

-.Ss \&trnt
+.It Ic \&trnt Ar glyph glyph ...

 Output character translation, ignored by \e!.
 Currently unsupported.
 Output character translation, ignored by \e!.
 Currently unsupported.

-.Ss \&troff
+.It Ic \&troff

 Force troff mode.
 This is a groff extension and currently ignored.
 Force troff mode.
 This is a groff extension and currently ignored.

-.Ss \&TS
+.It Ic \&TS

 Begin a table, which formats input in aligned rows and columns.
 See
 .Xr tbl 7
 for a description of the tbl language.
 Begin a table, which formats input in aligned rows and columns.
 See
 .Xr tbl 7
 for a description of the tbl language.

-.Ss \&uf
+.It Ic \&uf Ar font

 Globally set the underline font.
 Currently ignored.
 Globally set the underline font.
 Currently ignored.

-.Ss \&ul
-Underline.
+.It Ic \&ul Op Ar N
+Underline next
+.Ar N
+input lines.

 Currently ignored.
 Currently ignored.

-.Ss \&unformat
+.It Ic \&unformat Ar divname

 Unformat spaces and tabs in a diversion.
 Currently unsupported.
 Unformat spaces and tabs in a diversion.
 Currently unsupported.

-.Ss \&unwatch
+.It Ic \&unwatch Ar macroname

 Disable notification for string or macro.
 This is a Heirloom extension and currently ignored.
 Disable notification for string or macro.
 This is a Heirloom extension and currently ignored.

-.Ss \&unwatchn
+.It Ic \&unwatchn Ar register

 Disable notification for register.
 This is a Heirloom extension and currently ignored.
 Disable notification for register.
 This is a Heirloom extension and currently ignored.

-.Ss \&vpt
+.It Ic \&vpt Op Cm 1 | 0

 Enable or disable vertical position traps.
 This is a groff extension and currently ignored.
 Enable or disable vertical position traps.
 This is a groff extension and currently ignored.

-.Ss \&vs
+.It Ic \&vs Op Oo Cm + Ns | Ns Cm - Oc Ns Ar height

 Change vertical spacing.
 Currently ignored.
 Change vertical spacing.
 Currently ignored.

-.Ss \&warn
+.It Ic \&warn Ar flags

 Set warning level.
 Currently ignored.
 Set warning level.
 Currently ignored.

-.Ss \&warnscale
+.It Ic \&warnscale Ar si

 Set the scaling indicator used in warnings.
 This is a groff extension and currently ignored.
 Set the scaling indicator used in warnings.
 This is a groff extension and currently ignored.

-.Ss \&watch
+.It Ic \&watch Ar macroname

 Notify on change of string or macro.
 This is a Heirloom extension and currently ignored.
 Notify on change of string or macro.
 This is a Heirloom extension and currently ignored.

-.Ss \&watchlength
+.It Ic \&watchlength Ar maxlength

 On change, report the contents of macros and strings
 On change, report the contents of macros and strings

-up to the sepcified length.
+up to the specified length.

 This is a Heirloom extension and currently ignored.
 This is a Heirloom extension and currently ignored.

-.Ss \&watchn
+.It Ic \&watchn Ar register

 Notify on change of register.
 This is a Heirloom extension and currently ignored.
 Notify on change of register.
 This is a Heirloom extension and currently ignored.

-.Ss \&wh
+.It Ic \&wh Ar dist Op Ar macroname

 Set a page location trap.
 Currently unsupported.
 Set a page location trap.
 Currently unsupported.

-.Ss \&while
+.It Ic \&while Ar condition body

 Repeated execution while a condition is true.
 Currently unsupported.
 Repeated execution while a condition is true.
 Currently unsupported.

-.Ss \&write
+.It Ic \&write Oo \(dq Oc Ns Ar string

 Write to an open file.
 Ignored because insecure.
 Write to an open file.
 Ignored because insecure.

-.Ss \&writec
+.It Ic \&writec Oo \(dq Oc Ns Ar string

 Write to an open file without appending a newline.
 Ignored because insecure.
 Write to an open file without appending a newline.
 Ignored because insecure.

-.Ss \&writem
+.It Ic \&writem Ar macroname

 Write macro or string to an open file.
 Ignored because insecure.
 Write macro or string to an open file.
 Ignored because insecure.

-.Ss \&xflag
+.It Ic \&xflag Ar level

 Set the extension level.
 This is a Heirloom extension and currently ignored.
 Set the extension level.
 This is a Heirloom extension and currently ignored.

+.El

 .Ss Numerical expressions
 The
 .Sx \&nr ,
 .Ss Numerical expressions
 The
 .Sx \&nr ,


@@ -1715,6 +1743,14 @@ prefixed by an optional sign
 .Sq +
 or
 .Sq - .
 .Sq +
 or
 .Sq - .

+Each number may be followed by one optional scaling unit described below
+.Sx Scaling Widths .
+The following equations hold:
+.Bd -literal -offset indent
+1i = 6v = 6P = 10m = 10n = 72p = 1000M = 240u = 240
+254c = 100i = 24000u = 24000
+1f = 65536u = 65536
+.Ed

 .Pp
 The following binary operators are implemented.
 Unless otherwise stated, they behave as in the C language:
 .Pp
 The following binary operators are implemented.
 Unless otherwise stated, they behave as in the C language:


@@ -1754,15 +1790,15 @@ logical and (corresponds to C
 .Ic && )
 .It Ic \&:
 logical or (corresponds to C
 .Ic && )
 .It Ic \&:
 logical or (corresponds to C

-.Ic \&|| )
+.Ic || )

 .It Ic <?
 minimum (not available in C)
 .It Ic >?
 maximum (not available in C)
 .El
 .Pp
 .It Ic <?
 minimum (not available in C)
 .It Ic >?
 maximum (not available in C)
 .El
 .Pp

-There is no concept of precendence; evaluation proceeds from left to right,
-except when subexpressions are enclosed in parantheses.
+There is no concept of precedence; evaluation proceeds from left to right,
+except when subexpressions are enclosed in parentheses.

 Inside parentheses, whitespace is ignored.
 .Sh ESCAPE SEQUENCE REFERENCE
 The
 Inside parentheses, whitespace is ignored.
 .Sh ESCAPE SEQUENCE REFERENCE
 The


@@ -1796,6 +1832,12 @@ is an unpaddable space-sized non-breaking space character; see
 .Ss \e\(dq
 The rest of the input line is treated as
 .Sx Comments .
 .Ss \e\(dq
 The rest of the input line is treated as
 .Sx Comments .

+.Ss \e#
+Line continuation with comment.
+Discard the rest of the physical input line and continue the logical
+input line on the next physical input line, joining the text on
+both lines together as if it were on a single input line.
+This is a groff extension.

 .Ss \e%
 Hyphenation allowed at this point of the word; ignored by
 .Xr mandoc 1 .
 .Ss \e%
 Hyphenation allowed at this point of the word; ignored by
 .Xr mandoc 1 .


@@ -1810,21 +1852,42 @@ instead.
 .Sx Special Characters
 with two-letter names, see
 .Xr mandoc_char 7 .
 .Sx Special Characters
 with two-letter names, see
 .Xr mandoc_char 7 .

-.Ss \e*[ Ns Ar name ]
+.Ss \e* Ns Bq Ar name

 Interpolate the string with the
 Interpolate the string with the

-.Ar name ;
-see
-.Sx Predefined Strings
-and
-.Sx ds .
+.Ar name .

 For short names, there are variants
 .No \e* Ns Ar c
 and
 .No \e*( Ns Ar cc .
 For short names, there are variants
 .No \e* Ns Ar c
 and
 .No \e*( Ns Ar cc .

+.Pp
+One string is predefined on the
+.Nm
+language level: \e*(.T expands to the name of the output device,
+for example ascii, utf8, ps, pdf, html, or markdown.
+.Pp
+Macro sets traditionally predefine additional strings which are not
+portable and differ across implementations.
+Those supported by
+.Xr mandoc 1
+are listed in
+.Xr mandoc_char 7 .
+.Pp
+Strings can be defined, changed, and deleted with the
+.Ic \&ds ,
+.Ic \&as ,
+and
+.Ic \&rm
+requests.
+.Ss \e,
+Left italic correction (groff extension); ignored by
+.Xr mandoc 1 .

 .Ss \e-
 Special character
 .Dq mathematical minus sign .
 .Ss \e-
 Special character
 .Dq mathematical minus sign .

-.Ss \e[ Ns Ar name ]
+.Ss \e/
+Right italic correction (groff extension); ignored by
+.Xr mandoc 1 .
+.Ss \e Ns Bq Ar name

 .Sx Special Characters
 with names of arbitrary length, see
 .Xr mandoc_char 7 .
 .Sx Special Characters
 with names of arbitrary length, see
 .Xr mandoc_char 7 .


@@ -1880,14 +1943,14 @@ Move down by half a line; ignored by
 .Xr mandoc 1 .
 .Ss \ee
 Backslash special character.
 .Xr mandoc 1 .
 .Ss \ee
 Backslash special character.

-.Ss \eF[ Ns Ar name ]
+.Ss \eF Ns Bq Ar name

 Switch font family (groff extension); ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 .No \eF Ns Ar c
 and
 .No \eF( Ns Ar cc .
 Switch font family (groff extension); ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 .No \eF Ns Ar c
 and
 .No \eF( Ns Ar cc .

-.Ss \ef[ Ns Ar name ]
+.Ss \ef Ns Bq Ar name

 Switch to the font
 .Ar name ,
 see
 Switch to the font
 .Ar name ,
 see


@@ -1896,7 +1959,7 @@ For short names, there are variants
 .No \ef Ns Ar c
 and
 .No \ef( Ns Ar cc .
 .No \ef Ns Ar c
 and
 .No \ef( Ns Ar cc .

-.Ss \eg[ Ns Ar name ]
+.Ss \eg Ns Bq Ar name

 Interpolate the format of a number register; ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 Interpolate the format of a number register; ignored by
 .Xr mandoc 1 .
 For short names, there are variants


@@ -1906,10 +1969,14 @@ and
 .Ss \eH\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
 Set the height of the current font; ignored by
 .Xr mandoc 1 .
 .Ss \eH\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
 Set the height of the current font; ignored by
 .Xr mandoc 1 .

-.Ss \eh\(aq Ns Ar number Ns \(aq
-Horizontal motion; ignored by
-.Xr mandoc 1 .
-.Ss \ek[ Ns Ar name ]
+.Ss \eh\(aq Ns Oo Cm \&| Oc Ns Ar width Ns \(aq
+Horizontal motion.
+If the vertical bar is given, the motion is relative to the current
+indentation.
+Otherwise, it is relative to the current position.
+The default scaling unit is
+.Cm m .
+.Ss \ek Ns Bq Ar name

 Mark horizontal input place in register; ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 Mark horizontal input place in register; ignored by
 .Xr mandoc 1 .
 For short names, there are variants


@@ -1919,17 +1986,19 @@ and
 .Ss \eL\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
 Vertical line drawing function; ignored by
 .Xr mandoc 1 .
 .Ss \eL\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
 Vertical line drawing function; ignored by
 .Xr mandoc 1 .

-.Ss \el\(aq Ns Ar number Ns Oo Ar c Oc Ns \(aq
-Horizontal line drawing function; ignored by
-.Xr mandoc 1 .
-.Ss \eM[ Ns Ar name ]
+.Ss \el\(aq Ns Ar width Ns Oo Ar c Oc Ns \(aq
+Draw a horizontal line of
+.Ar width
+using the glyph
+.Ar c .
+.Ss \eM Ns Bq Ar name

 Set fill (background) color (groff extension); ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 .No \eM Ns Ar c
 and
 .No \eM( Ns Ar cc .
 Set fill (background) color (groff extension); ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 .No \eM Ns Ar c
 and
 .No \eM( Ns Ar cc .

-.Ss \em[ Ns Ar name ]
+.Ss \em Ns Bq Ar name

 Set glyph drawing color (groff extension); ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 Set glyph drawing color (groff extension); ignored by
 .Xr mandoc 1 .
 For short names, there are variants


@@ -1940,19 +2009,27 @@ and
 Character
 .Ar number
 on the current font.
 Character
 .Ar number
 on the current font.

-.Ss \en[ Ns Ar name ]
+.Ss \en Ns Oo +|- Oc Ns Bq Ar name

 Interpolate the number register
 .Ar name .
 For short names, there are variants
 .No \en Ns Ar c
 and
 .No \en( Ns Ar cc .
 Interpolate the number register
 .Ar name .
 For short names, there are variants
 .No \en Ns Ar c
 and
 .No \en( Ns Ar cc .

+If the optional sign is specified,
+the register is first incremented or decremented by the
+.Ar stepsize
+that was specified in the relevant
+.Ic \&nr
+request, and the changed value is interpolated.

 .Ss \eo\(aq Ns Ar string Ns \(aq
 .Ss \eo\(aq Ns Ar string Ns \(aq

-Overstrike, that is, write all the characters contained in the
+Overstrike, writing all the characters contained in the

 .Ar string
 to the same output position.
 In terminal and HTML output modes,
 only the last one of the characters is visible.
 .Ar string
 to the same output position.
 In terminal and HTML output modes,
 only the last one of the characters is visible.

+.Ss \ep
+Break the output line at the end of the current word.

 .Ss \eR\(aq Ns Ar name Oo +|- Oc Ns Ar number Ns \(aq
 Set number register; ignored by
 .Xr mandoc 1 .
 .Ss \eR\(aq Ns Ar name Oo +|- Oc Ns Ar number Ns \(aq
 Set number register; ignored by
 .Xr mandoc 1 .


@@ -1965,9 +2042,9 @@ Change point size; ignored by
 Alternative forms
 .No \es Ns Oo +|- Oc Ns Ar n ,
 .No \es Ns Oo +|- Oc Ns \(aq Ns Ar number Ns \(aq ,
 Alternative forms
 .No \es Ns Oo +|- Oc Ns Ar n ,
 .No \es Ns Oo +|- Oc Ns \(aq Ns Ar number Ns \(aq ,

-.No \es Ns [ Oo +|- Oc Ns Ar number ] ,
+.No \es Ns Bq Oo +|- Oc Ns Ar number ,

 and
 and

-.No \es Ns Oo +|- Oc Ns [ Ar number Ns ]
+.No \es Ns Oo +|- Oc Ns Bq Ar number

 are also parsed and ignored.
 .Ss \et
 Horizontal tab; ignored by
 are also parsed and ignored.
 .Ss \et
 Horizontal tab; ignored by


@@ -1975,7 +2052,7 @@ Horizontal tab; ignored by
 .Ss \eu
 Move up by half a line; ignored by
 .Xr mandoc 1 .
 .Ss \eu
 Move up by half a line; ignored by
 .Xr mandoc 1 .

-.Ss \eV[ Ns Ar name ]
+.Ss \eV Ns Bq Ar name

 Interpolate an environment variable; ignored by
 .Xr mandoc 1 .
 For short names, there are variants
 Interpolate an environment variable; ignored by
 .Xr mandoc 1 .
 For short names, there are variants


@@ -2002,7 +2079,7 @@ as device control function; ignored in nroff mode and by
 .Ss \ex\(aq Ns Ar number Ns \(aq
 Extra line space function; ignored by
 .Xr mandoc 1 .
 .Ss \ex\(aq Ns Ar number Ns \(aq
 Extra line space function; ignored by
 .Xr mandoc 1 .

-.Ss \eY[ Ns Ar name ]
+.Ss \eY Ns Bq Ar name

 Output a string as a device control function; ignored in nroff mode and by
 .Xr mandoc 1 .
 For short names, there are variants
 Output a string as a device control function; ignored in nroff mode and by
 .Xr mandoc 1 .
 For short names, there are variants


@@ -2015,55 +2092,68 @@ Print
 with zero width and height; ignored by
 .Xr mandoc 1 .
 .Ss \ez
 with zero width and height; ignored by
 .Xr mandoc 1 .
 .Ss \ez

-Output the next character without advancing the cursor position;
-approximated in
-.Xr mandoc 1
-by simply skipping the next character.
+Output the next character without advancing the cursor position.

 .Sh COMPATIBILITY
 .Sh COMPATIBILITY

-This section documents compatibility between mandoc and other
+The
+.Xr mandoc 1
+implementation of the

 .Nm
 .Nm

-implementations, at this time limited to GNU troff
-.Pq Qq groff .
-The term
-.Qq historic groff
-refers to groff version 1.15.
+language is intentionally incomplete.
+Unimplemented features include:

 .Pp
 .Bl -dash -compact
 .It
 .Pp
 .Bl -dash -compact
 .It

+For security reasons,
+.Xr mandoc 1
+never reads or writes external files except via
+.Sx \&so
+requests with safe relative paths.
+.It
+There is no automatic hyphenation, no adjustment to the right margin,
+and no centering; the output is always set flush-left.
+.It
+Support for setting tabulator positions
+and tabulator and leader characters is missing,
+and support for manually changing indentation is limited.
+.It

 The
 .Sq u
 scaling unit is the default terminal unit.
 The
 .Sq u
 scaling unit is the default terminal unit.

-In traditional troff systems, this unit would change depending on the
+In traditional troff systems, this unit changes depending on the

 output media.
 .It
 output media.
 .It

-In mandoc, the
-.Sx \&EQ ,
-.Sx \&TE ,
-.Sx \&TS ,
-and
-.Sx \&T& ,
-macros are considered regular macros.
-In all other
-.Nm
-implementations, these are special macros that must be specified without
-spacing between the control character (which must be a period) and the
-macro name.
+Width measurements are implemented in a crude way
+and often yield wrong results.
+Explicit movement requests and escapes are ignored.

 .It
 .It

-The
-.Cm nS
-register is only compatible with OpenBSD's groff-1.15.
+There is no concept of output pages, no support for floats,
+graphics drawing, and picture inclusion;
+terminal output is always continuous.

 .It
 .It

-Historic groff did not accept white-space before a custom
-.Ar end
-macro for the
-.Sx \&ig
-request.
+Requests regarding color, font families, and glyph manipulation
+are ignored.
+Font support is very limited.
+Kerning is not implemented, and no ligatures are produced.

 .It
 The
 .It
 The

-.Sx \&if
-and family would print funny white-spaces with historic groff when
-using the next-line syntax.
+.Qq \(aq
+macro control character does not suppress output line breaks.
+.It
+Diversions are not implemented,
+and support for traps is very incomplete.
+.It
+While recursion is supported,
+.Sx \&while
+loops are not.

 .El
 .El

+.Pp
+The special semantics of the
+.Cm nS
+number register is an idiosyncracy of
+.Ox
+manuals and not supported by other
+.Xr mdoc 7
+implementations.

 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr eqn 7 ,
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr eqn 7 ,