Fix mandocdb(8) -d and -u.

[mandoc.git] / roff.7

diff --git a/roff.7 b/roff.7
index 96152520043a0fd48eb095b3973e208e999a92f6..48e16dd905bd3a752306fbb123cde150de1f0858 100644 (file)
--- a/roff.7
+++ b/roff.7
@@ -1,6 +1,7 @@
-.\"    $Id: roff.7,v 1.7 2010/05/24 23:54:18 schwarze Exp $
+.\"    $Id: roff.7,v 1.46 2013/12/26 02:43:18 schwarze Exp $

 .\"
 .\"

-.\" Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010, 2011, 2013 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


@@ -14,93 +15,609 @@
 .\" 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: May 24 2010 $
+.Dd $Mdocdate: December 26 2013 $

 .Dt ROFF 7
 .Os
 .Sh NAME
 .Nm roff
 .Dt ROFF 7
 .Os
 .Sh NAME
 .Nm roff

-.Nd roff language reference
+.Nd roff language reference for mandoc

 .Sh DESCRIPTION
 The
 .Nm roff
 .Sh DESCRIPTION
 The
 .Nm roff

-language is a general-purpose text-formatting language.  The purpose of
-this document is to consistently describe those language constructs
-accepted by the
+language is a general purpose text formatting language.
+Since traditional implementations of the
+.Xr mdoc 7
+and
+.Xr man 7
+manual formatting languages are based on it,
+many real-world manuals use small numbers of
+.Nm
+requests and escape sequences intermixed with their
+.Xr mdoc 7
+or
+.Xr man 7
+code.
+To properly format such manuals, the

 .Xr mandoc 1
 .Xr mandoc 1

-utility.  It is a work in progress.
-.Pp
-An
+utility supports a tiny subset of

 .Nm
 .Nm

-document follows simple rules:  lines beginning with the control
-characters
-.Sq \.
+requests and escapes.
+Only these requests and escapes supported by
+.Xr mandoc 1
+are documented in the present manual,
+together with the basic language syntax shared by
+.Nm ,
+.Xr mdoc 7 ,
+and
+.Xr man 7 .
+For complete
+.Nm
+manuals, consult the
+.Sx SEE ALSO
+section.
+.Pp
+Input lines beginning with the control character
+.Sq \&.
+are parsed for requests and macros.
+Such lines are called
+.Dq request lines

 or
 or

-.Sq \(aq
-are parsed for macros.  Other lines are interpreted within the scope of
-prior macros:
-.Bd -literal -offset indent
-\&.xx Macro lines change control state.
-Other lines are interpreted within the current state.
-.Ed
+.Dq macro lines ,
+respectively.
+Requests change the processing state and manipulate the formatting;
+some macros also define the document structure and produce formatted
+output.
+The single quote
+.Pq Qq \(aq
+is accepted as an alternative control character,
+treated by
+.Xr mandoc 1
+just like
+.Ql \&.
+.Pp
+Lines not beginning with control characters are called
+.Dq text lines .
+They provide free-form text to be printed; the formatting of the text
+depends on the respective processing context.

 .Sh LANGUAGE SYNTAX
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the space
 .Sh LANGUAGE SYNTAX
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the space

-character, and, in certain circumstances, the tab character.  All
-manuals must have
-.Ux
-line terminators.
-.Sh MACRO SYNTAX
-Macros are arbitrary in length and begin with a control character ,
-.Sq \.
+character, and, in certain circumstances, the tab character.
+The backslash character
+.Sq \e
+indicates the start of an escape sequence, used for example for
+.Sx Comments ,
+.Sx Special Characters ,
+.Sx Predefined Strings ,
+and
+user-defined strings defined using the
+.Sx ds
+request.
+For a listing of escape sequences, consult the
+.Sx ESCAPE SEQUENCE REFERENCE
+below.
+.Ss Comments
+Text following an escaped double-quote
+.Sq \e\(dq ,
+whether in a request, macro, or text line, is ignored to the end of the line.
+A request line beginning with a control character and comment escape
+.Sq \&.\e\(dq
+is also ignored.
+Furthermore, request lines with only a control character and optional
+trailing whitespace are stripped from input.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.\e\(dq This is a comment line.
+\&.\e\(dq The next line is ignored:
+\&.
+\&.Sh EXAMPLES \e\(dq This is a comment, too.
+\&example text \e\(dq And so is this.
+.Ed
+.Ss Special Characters
+Special characters are used to encode special glyphs and are rendered
+differently across output media.
+They may occur in request, macro, and text lines.
+Sequences begin with the escape character
+.Sq \e
+followed by either an open-parenthesis
+.Sq \&(
+for two-character sequences; an open-bracket
+.Sq \&[
+for n-character sequences (terminated at a close-bracket
+.Sq \&] ) ;
+or a single one character sequence.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \e(em
+Two-letter em dash escape.
+.It Li \ee
+One-letter backslash escape.
+.El
+.Pp
+See
+.Xr mandoc_char 7
+for a complete list.
+.Ss Text Decoration
+Terms may be text-decorated using the
+.Sq \ef
+escape followed by an indicator: B (bold), I (italic), R (regular), or P
+(revert to previous mode).
+A numerical representation 3, 2, or 1 (bold, italic, and regular,
+respectively) may be used instead.
+The indicator or numerical representative may be preceded by C
+(constant-width), which is ignored.
+.Pp
+The two-character indicator
+.Sq BI
+requests a font that is both bold and italic.
+It may not be portable to old roff implementations.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li \efBbold\efR
+Write in \fBbold\fP, then switch to regular font mode.
+.It Li \efIitalic\efP
+Write in \fIitalic\fP, then return to previous font mode.
+.It Li \ef(BIbold italic\efP
+Write in \f(BIbold italic\fP, then return to previous font mode.
+.El
+.Pp
+Text decoration is
+.Em not
+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.
+In request and macro lines, whitespace delimits arguments and is discarded.
+.Pp
+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.
+In the rare case that a blank character is needed at the end of an
+input line, it may be forced by
+.Sq \e\ \e& .
+.Pp
+Literal space characters can be produced in the output
+using escape sequences.
+In macro lines, they can also be included in arguments using quotation; see
+.Sx MACRO SYNTAX
+for details.
+.Pp
+Blank text lines, which may include whitespace, are only permitted
+within literal contexts.
+If the first character of a text line is a space, that line is printed
+with a leading newline.
+.Ss Scaling Widths
+Many requests and macros support scaled widths for their arguments.
+The syntax for a scaled width is
+.Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,
+where a decimal must be preceded or followed by at least one digit.
+Negative numbers, while accepted, are truncated to zero.
+.Pp
+The following scaling units are accepted:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It c
+centimetre
+.It i
+inch
+.It P
+pica (~1/6 inch)
+.It p
+point (~1/72 inch)
+.It f
+synonym for
+.Sq u
+.It v
+default vertical span
+.It m
+width of rendered
+.Sq m
+.Pq em
+character
+.It n
+width of rendered
+.Sq n
+.Pq en
+character
+.It u
+default horizontal span
+.It M
+mini-em (~1/100 em)
+.El
+.Pp
+Using anything other than
+.Sq m ,
+.Sq n ,
+.Sq u ,
+or
+.Sq v
+is necessarily non-portable across output media.
+See
+.Sx COMPATIBILITY .
+.Pp
+If a scaling unit is not provided, the numerical value is interpreted
+under the default rules of
+.Sq v
+for vertical spaces and
+.Sq u
+for horizontal ones.
+.Pp
+Examples:
+.Bl -tag -width ".Bl -tag -width 2i" -offset indent -compact
+.It Li \&.Bl -tag -width 2i
+two-inch tagged list indentation in
+.Xr mdoc 7
+.It Li \&.HP 2i
+two-inch tagged list indentation in
+.Xr man 7
+.It Li \&.sp 2v
+two vertical spaces
+.El
+.Ss Sentence Spacing
+Each sentence should terminate at the end of an input line.
+By doing this, a formatter will be able to apply the proper amount of
+spacing after the end of sentence (unescaped) period, exclamation mark,
+or question mark followed by zero or more non-sentence closing
+delimiters
+.Po
+.Sq \&) ,
+.Sq \&] ,
+.Sq \&' ,
+.Sq \&"
+.Pc .
+.Pp
+The proper spacing is also intelligently preserved if a sentence ends at
+the boundary of a macro line.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+Do not end sentences mid-line like this.  Instead,
+end a sentence like this.
+A macro would end like this:
+\&.Xr mandoc 1 \&.
+.Ed
+.Sh REQUEST SYNTAX
+A request or macro line consists of:
+.Pp
+.Bl -enum -compact
+.It
+the control character
+.Sq \&.

 or
 or

-.Sq \(aq ,
-at the beginning of the line.
-An arbitrary amount of whitespace may sit between the control character
-and the macro name.
-Thus, the following are equivalent:
+.Sq \(aq
+at the beginning of the line,
+.It
+optionally an arbitrary amount of whitespace,
+.It
+the name of the request or the macro, which is one word of arbitrary
+length, terminated by whitespace,
+.It
+and zero or more arguments delimited by whitespace.
+.El
+.Pp
+Thus, the following request lines are all equivalent:

 .Bd -literal -offset indent
 .Bd -literal -offset indent

-\&.if
-\&.\ \ \ \&if
+\&.ig end
+\&.ig    end
+\&.   ig end

 .Ed
 .Ed

-.Sh REFERENCE
-This section is a canonical reference of all macros, arranged
-alphabetically.
+.Sh MACRO SYNTAX
+Macros are provided by the
+.Xr mdoc 7
+and
+.Xr man 7
+languages and can be defined by the
+.Sx \&de
+request.
+When called, they follow the same syntax as requests, except that
+macro arguments may optionally be quoted by enclosing them
+in double quote characters
+.Pq Sq \(dq .
+Quoted text, even if it contains whitespace or would cause
+a macro invocation when unquoted, is always considered literal text.
+Inside quoted text, pairs of double quote characters
+.Pq Sq Qq
+resolve to single double quote characters.
+.Pp
+To be recognised as the beginning of a quoted argument, the opening
+quote character must be preceded by a space character.
+A quoted argument extends to the next double quote character that is not
+part of a pair, or to the end of the input line, whichever comes earlier.
+Leaving out the terminating double quote character at the end of the line
+is discouraged.
+For clarity, if more arguments follow on the same input line,
+it is recommended to follow the terminating double quote character
+by a space character; in case the next character after the terminating
+double quote character is anything else, it is regarded as the beginning
+of the next, unquoted argument.
+.Pp
+Both in quoted and unquoted arguments, pairs of backslashes
+.Pq Sq \e\e
+resolve to single backslashes.
+In unquoted arguments, space characters can alternatively be included
+by preceding them with a backslash
+.Pq Sq \e\~ ,
+but quoting is usually better for clarity.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It Li .Fn strlen \(dqconst char *s\(dq
+Group arguments
+.Qq const char *s
+into one function argument.
+If unspecified,
+.Qq const ,
+.Qq char ,
+and
+.Qq *s
+would be considered separate arguments.
+.It Li .Op \(dqFl a\(dq
+Consider
+.Qq \&Fl a
+as literal text instead of a flag macro.
+.El
+.Sh REQUEST REFERENCE
+The
+.Xr mandoc 1
+.Nm
+parser recognises the following requests.
+Note that the
+.Nm
+language defines many more requests not implemented in
+.Xr mandoc 1 .
+.Ss \&ad
+Set line adjustment mode.
+This line-scoped request is intended to have one argument to select
+normal, left, right, or centre adjustment for subsequent text.
+Currently, it is ignored including its arguments,
+and the number of arguments is not checked.

 .Ss \&am
 .Ss \&am

-The syntax of this macro is the same as that of
-.Sx \&ig ,
-except that a leading argument must be specified.
-It is ignored, as are its children.
+Append to a macro definition.
+The syntax of this request is the same as that of
+.Sx \&de .
+It is currently ignored by
+.Xr mandoc 1 ,
+as are its children.

 .Ss \&ami
 .Ss \&ami

-The syntax of this macro is the same as that of
-.Sx \&ig ,
-except that a leading argument must be specified.
-It is ignored, as are its children.
+Append to a macro definition, specifying the macro name indirectly.
+The syntax of this request is the same as that of
+.Sx \&dei .
+It is currently ignored by
+.Xr mandoc 1 ,
+as are its children.

 .Ss \&am1
 .Ss \&am1

-The syntax of this macro is the same as that of
-.Sx \&ig ,
-except that a leading argument must be specified.
-It is ignored, as are its children.
+Append to a macro definition, switching roff compatibility mode off
+during macro execution.
+The syntax of this request is the same as that of
+.Sx \&de1 .
+It is currently ignored by
+.Xr mandoc 1 ,
+as are its children.
+.Ss \&cc
+Changes the control character.
+Its syntax is as follows:
+.Bd -literal -offset indent
+.Pf . Cm \&cc Op Ar c
+.Ed
+.Pp
+If
+.Ar c
+is not specified, the control character is reset to
+.Sq \&. .
+Trailing characters are ignored.

 .Ss \&de
 .Ss \&de

-The syntax of this macro is the same as that of
-.Sx \&ig ,
-except that a leading argument must be specified.
-It is ignored, as are its children.
+Define a
+.Nm
+macro.
+Its syntax can be either
+.Bd -literal -offset indent
+.Pf . Cm \&de Ar name
+.Ar macro definition
+\&..
+.Ed
+.Pp
+or
+.Bd -literal -offset indent
+.Pf . Cm \&de Ar name Ar end
+.Ar macro definition
+.Pf . Ar end
+.Ed
+.Pp
+Both forms define or redefine the macro
+.Ar name
+to represent the
+.Ar macro definition ,
+which may consist of one or more input lines, including the newline
+characters terminating each line, optionally containing calls to
+.Nm
+requests,
+.Nm
+macros or high-level macros like
+.Xr man 7
+or
+.Xr mdoc 7
+macros, whichever applies to the document in question.
+.Pp
+Specifying a custom
+.Ar end
+macro works in the same way as for
+.Sx \&ig ;
+namely, the call to
+.Sq Pf . Ar end
+first ends the
+.Ar macro definition ,
+and after that, it is also evaluated as a
+.Nm
+request or
+.Nm
+macro, but not as a high-level macro.
+.Pp
+The macro can be invoked later using the syntax
+.Pp
+.D1 Pf . Ar name Op Ar argument Op Ar argument ...
+.Pp
+Regarding argument parsing, see
+.Sx MACRO SYNTAX
+above.
+.Pp
+The line invoking the macro will be replaced
+in the input stream by the
+.Ar macro definition ,
+replacing all occurrences of
+.No \e\e$ Ns Ar N ,
+where
+.Ar N
+is a digit, by the
+.Ar N Ns th Ar argument .
+For example,
+.Bd -literal -offset indent
+\&.de ZN
+\efI\e^\e\e$1\e^\efP\e\e$2
+\&..
+\&.ZN XtFree .
+.Ed
+.Pp
+produces
+.Pp
+.D1 \efI\e^XtFree\e^\efP.
+.Pp
+in the input stream, and thus in the output: \fI\^XtFree\^\fP.
+.Pp
+Since macros and user-defined strings share a common string table,
+defining a macro
+.Ar name
+clobbers the user-defined string
+.Ar name ,
+and the
+.Ar macro definition
+can also be printed using the
+.Sq \e*
+string interpolation syntax described below
+.Sx ds ,
+but this is rarely useful because every macro definition contains at least
+one explicit newline character.
+.Pp
+In order to prevent endless recursion, both groff and
+.Xr mandoc 1
+limit the stack depth for expanding macros and strings
+to a large, but finite number.
+Do not rely on the exact value of this limit.

 .Ss \&dei
 .Ss \&dei

-The syntax of this macro is the same as that of
-.Sx \&ig ,
-except that a leading argument must be specified.
-It is ignored, as are its children.
-.Ss \&ds
-Define a string.
-This macro is intended to have two arguments,
-the name of the string to define and its content.
-Currently, it is ignored including its arguments,
-and the number of arguments is not checked.
+Define a
+.Nm
+macro, specifying the macro name indirectly.
+The syntax of this request is the same as that of
+.Sx \&de .
+It is currently ignored by
+.Xr mandoc 1 ,
+as are its children.

 .Ss \&de1
 .Ss \&de1

-The syntax of this macro is the same as that of
-.Sx \&ig ,
-except that a leading argument must be specified.
-It is ignored, as are its children.
+Define a
+.Nm
+macro that will be executed with
+.Nm
+compatibility mode switched off during macro execution.
+This is a GNU extension not available in traditional
+.Nm
+implementations and not even in older versions of groff.
+Since
+.Xr mandoc 1
+does not implement
+.Nm
+compatibility mode at all, it handles this request as an alias for
+.Sx \&de .
+.Ss \&ds
+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
+.Ar name
+and
+.Ar string
+arguments are space-separated.
+If the
+.Ar string
+begins with a double-quote character, that character will not be part
+of the string.
+All remaining characters on the input line form the
+.Ar string ,
+including whitespace and double-quote characters, even trailing ones.
+.Pp
+The
+.Ar string
+can be interpolated into subsequent text by using
+.No \e* Ns Bq Ar name
+for a
+.Ar name
+of arbitrary length, or \e*(NN or \e*N if the length of
+.Ar name
+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
+does not trigger string interpolation.
+.Pp
+Since user-defined strings and macros share a common string table,
+defining a string
+.Ar name
+clobbers the macro
+.Ar name ,
+and the
+.Ar name
+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 ,
+forming a new input line passed to the
+.Nm
+parser.
+For example,
+.Bd -literal -offset indent
+\&.ds badidea .S
+\&.badidea
+H SYNOPSIS
+.Ed
+.Pp
+invokes the
+.Cm SH
+macro when used in a
+.Xr man 7
+document.
+Such abuse is of course strongly discouraged.

 .Ss \&el
 The
 .Qq else
 .Ss \&el
 The
 .Qq else


@@ -112,9 +629,30 @@ If no stack entries are present (e.g., due to no prior
 .Sx \&ie
 calls)
 then false is assumed.
 .Sx \&ie
 calls)
 then false is assumed.

-The syntax of this macro is similar to
+The syntax of this request is similar to

 .Sx \&if
 except that the conditional is missing.
 .Sx \&if
 except that the conditional is missing.

+.Ss \&EN
+End an equation block.
+See
+.Sx \&EQ .
+.Ss \&EQ
+Begin an equation block.
+See
+.Xr eqn 7
+for a description of the equation language.
+.Ss \&fam
+Change the font family.
+This line-scoped request is intended to have one argument specifying
+the font family to be selected.
+It is a groff extension, and currently, it is ignored including its
+arguments, and the number of arguments is not checked.
+.Ss \&hw
+Specify hyphenation points in words.
+This line-scoped request is currently ignored.
+.Ss \&hy
+Set automatic hyphenation mode.
+This line-scoped request is currently ignored.

 .Ss \&ie
 The
 .Qq if
 .Ss \&ie
 The
 .Qq if


@@ -130,60 +668,66 @@ Begins a conditional.
 Right now, the conditional evaluates to true
 if and only if it starts with the letter
 .Sy n ,
 Right now, the conditional evaluates to true
 if and only if it starts with the letter
 .Sy n ,

-indicating processing in
-.Xr nroff 1
-style as opposed to
-.Xr troff 1
-style.
+indicating processing in nroff style as opposed to troff style.

 If a conditional is false, its children are not processed, but are
 syntactically interpreted to preserve the integrity of the input
 document.
 Thus,
 .Pp
 If a conditional is false, its children are not processed, but are
 syntactically interpreted to preserve the integrity of the input
 document.
 Thus,
 .Pp

-.D1 \&.if t \e .ig
+.D1 \&.if t .ig

 .Pp
 will discard the
 .Sq \&.ig ,
 which may lead to interesting results, but
 .Pp
 .Pp
 will discard the
 .Sq \&.ig ,
 which may lead to interesting results, but
 .Pp

-.D1 \&.if t \e .if t \e{\e
+.D1 \&.if t .if t \e{\e

 .Pp
 will continue to syntactically interpret to the block close of the final
 conditional.
 Sub-conditionals, in this case, obviously inherit the truth value of
 the parent.
 .Pp
 will continue to syntactically interpret to the block close of the final
 conditional.
 Sub-conditionals, in this case, obviously inherit the truth value of
 the parent.

-This macro has the following syntax:
-.Pp
-.Bd -literal -offset indent -compact
+This request has the following syntax:
+.Bd -literal -offset indent

 \&.if COND \e{\e
 BODY...
 \&.\e}
 .Ed
 \&.if COND \e{\e
 BODY...
 \&.\e}
 .Ed

-.Bd -literal -offset indent -compact
+.Bd -literal -offset indent

 \&.if COND \e{ BODY
 BODY... \e}
 .Ed
 \&.if COND \e{ BODY
 BODY... \e}
 .Ed

-.Bd -literal -offset indent -compact
+.Bd -literal -offset indent

 \&.if COND \e{ BODY
 BODY...
 \&.\e}
 .Ed
 \&.if COND \e{ BODY
 BODY...
 \&.\e}
 .Ed

-.Bd -literal -offset indent -compact
+.Bd -literal -offset indent

 \&.if COND \e
 BODY
 .Ed
 .Pp
 \&.if COND \e
 BODY
 .Ed
 .Pp

-COND is a conditional (for the time being, this always evaluates to
-false).
+COND is a conditional statement.
+roff allows for complicated conditionals; mandoc is much simpler.
+At this time, mandoc supports only
+.Sq n ,
+evaluating to true;
+and
+.Sq t ,
+.Sq e ,
+and
+.Sq o ,
+evaluating to false.
+All other invocations are read up to the next end of line or space and
+evaluate as false.

 .Pp
 If the BODY section is begun by an escaped brace
 .Sq \e{ ,
 .Pp
 If the BODY section is begun by an escaped brace
 .Sq \e{ ,

-scope continues until a closing-brace macro
+scope continues until a closing-brace escape sequence

 .Sq \.\e} .
 .Sq \.\e} .

-If the BODY is not enclosed in braces, scope continues until the next
-macro or word.
+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
 If the COND is followed by a BODY on the same line, whether after a

-brace or not, then macros
+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


@@ -194,98 +738,527 @@ bar
 \&.\e}
 .Ed
 .Pp
 \&.\e}
 .Ed
 .Pp

-than having the macro follow as
+than having the request or macro follow as

 .Pp
 .D1 \&.if COND \e{ .foo
 .Pp
 The scope of a conditional is always parsed, but only executed if the
 conditional evaluates to true.
 .Pp
 .Pp
 .D1 \&.if COND \e{ .foo
 .Pp
 The scope of a conditional is always parsed, but only executed if the
 conditional evaluates to true.
 .Pp

-Note that text subsequent a
-.Sq \&.\e}
-macro is discarded.
-Furthermore, if an explicit closing sequence
+Note that the

 .Sq \e}
 .Sq \e}

-is specified in a free-form line, the entire line is accepted within the
-scope of the prior macro, not only the text preceding the close.
+is converted into a zero-width escape sequence if not passed as a
+standalone macro
+.Sq \&.\e} .
+For example,
+.Pp
+.D1 \&.Fl a \e} b
+.Pp
+will result in
+.Sq \e}
+being considered an argument of the
+.Sq \&Fl
+macro.

 .Ss \&ig
 Ignore input.
 .Ss \&ig
 Ignore input.

-Accepts the following syntax:
-.Pp
-.Bd -literal -offset indent -compact
-\&.ig
-BODY...
+Its syntax can be either
+.Bd -literal -offset indent
+.Pf . Cm \&ig
+.Ar ignored text

 \&..
 .Ed
 \&..
 .Ed

-.Bd -literal -offset indent -compact
-\&.ig END
-BODY...
-\&.END
+.Pp
+or
+.Bd -literal -offset indent
+.Pf . Cm \&ig Ar end
+.Ar ignored text
+.Pf . Ar end

 .Ed
 .Pp
 In the first case, input is ignored until a
 .Sq \&..
 .Ed
 .Pp
 In the first case, input is ignored until a
 .Sq \&..

-macro is encountered on its own line.
-In the second case, input is ignored until a
-.Sq \&.END
-is encountered.
-Text subsequent the
-.Sq \&.END
-or
-.Sq \&..
-is discarded.
-.Pp
-Do not use the escape
+request is encountered on its own line.
+In the second case, input is ignored until the specified
+.Sq Pf . Ar end
+macro is encountered.
+Do not use the escape character

 .Sq \e
 .Sq \e

-anywhere in the definition of END.
-It causes very strange behaviour.
-Furthermore, if you redefine a
-.Nm
-macro, such as
+anywhere in the definition of
+.Ar end ;
+it would cause very strange behaviour.
+.Pp
+When the
+.Ar end
+macro is a roff request or a roff macro, like in

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

-will first signify the end of comment, then be invoked as a macro.
-This behaviour really shouldn't be counted upon.
+will first terminate the
+.Ar ignored text ,
+then be invoked as usual.
+Otherwise, it only terminates the
+.Ar ignored text ,
+and arguments following it or the
+.Sq \&..
+request are discarded.
+.Ss \&ne
+Declare the need for the specified minimum vertical space
+before the next trap or the bottom of the page.
+This line-scoped request is currently ignored.
+.Ss \&nh
+Turn off automatic hyphenation mode.
+This line-scoped request is currently ignored.

 .Ss \&rm
 Remove a request, macro or string.
 .Ss \&rm
 Remove a request, macro or string.

-This macro is intended to have one argument,
+This request is intended to have one argument,

 the name of the request, macro or string to be undefined.
 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.
 the name of the request, macro or string to be undefined.
 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.

-.Ss \&tr
-Output character translation.
-This macro is intended to have one argument,
-consisting of an even number of characters.
+.Ss \&nr
+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 value
+.Pp
+The
+.Ar value
+may, at the moment, only be an integer.
+If it is prefixed by a sign, the register will be
+incremented or decremented instead of assigned to.
+.Pp
+The following register
+.Ar name
+is handled specially:
+.Bl -tag -width Ds
+.It Cm nS
+If set to a positive integer value, certain
+.Xr mdoc 7
+macros will behave in the same way as in the
+.Em SYNOPSIS
+section.
+If set to 0, these macros will behave in the same way as outside the
+.Em SYNOPSIS
+section, even when called within the
+.Em SYNOPSIS
+section itself.
+Note that starting a new
+.Xr mdoc 7
+section with the
+.Cm \&Sh
+macro will reset this register.
+.El
+.Ss \&ns
+Turn on no-space mode.
+This line-scoped request is intended to take no arguments.
+Currently, it is ignored including its arguments,
+and the number of arguments is not checked.
+.Ss \&ps
+Change point size.
+This line-scoped request is intended to take one numerical argument.

 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.
 Currently, it is ignored including its arguments,
 and the number of arguments is not checked.

+.Ss \&so
+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
+request line.
+To avoid inadvertent inclusion of unrelated files,
+.Xr mandoc 1
+only accepts relative paths not containing the strings
+.Qq ../
+and
+.Qq /.. .
+.Pp
+This request requires
+.Xr man 1
+to change to the right directory before calling
+.Xr mandoc 1 ,
+per convention to the root of the manual tree.
+Typical usage looks like:
+.Pp
+.Dl \&.so man3/Xcursor.3
+.Pp
+As the whole concept is rather fragile, the use of
+.Sx \&so
+is discouraged.
+Use
+.Xr ln 1
+instead.
+.Ss \&ta
+Set tab stops.
+This line-scoped request can take an arbitrary number of arguments.
+Currently, it is ignored including its arguments.
+.Ss \&tr
+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,
+.Pp
+.Dl tr \e(xx\e(yy
+.Pp
+replaces all invocations of \e(xx with \e(yy.
+.Ss \&T&
+Re-start a table layout, retaining the options of the prior table
+invocation.
+See
+.Sx \&TS .
+.Ss \&TE
+End a table context.
+See
+.Sx \&TS .
+.Ss \&TS
+Begin a table, which formats input in aligned rows and columns.
+See
+.Xr tbl 7
+for a description of the tbl language.
+.Sh ESCAPE SEQUENCE REFERENCE
+The
+.Xr mandoc 1
+.Nm
+parser recognises the following escape sequences.
+Note that the
+.Nm
+language defines more escape sequences not implemented in
+.Xr mandoc 1 .
+In
+.Xr mdoc 7
+and
+.Xr man 7
+documents, using escape sequences is discouraged except for those
+described in the
+.Sx LANGUAGE SYNTAX
+section above.
+.Pp
+A backslash followed by any character not listed here
+simply prints that character itself.
+.Ss \e<newline>
+A backslash at the end of an input line can be used to 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.
+.Ss \e<space>
+The escape sequence backslash-space
+.Pq Sq \e\ \&
+is an unpaddable space-sized non-breaking space character; see
+.Sx Whitespace .
+.Ss \e\(dq
+The rest of the input line is treated as
+.Sx Comments .
+.Ss \e%
+Hyphenation allowed at this point of the word; ignored by
+.Xr mandoc 1 .
+.Ss \e&
+Non-printing zero-width character; see
+.Sx Whitespace .
+.Ss \e\(aq
+Acute accent special character; use
+.Sq \e(aa
+instead.
+.Ss \e( Ns Ar cc
+.Sx Special Characters
+with two-letter names, see
+.Xr mandoc_char 7 .
+.Ss \e*[ Ns Ar name ]
+Interpolate the string with the
+.Ar name ;
+see
+.Sx Predefined Strings
+and
+.Sx ds .
+For short names, there are variants
+.No \e* Ns Ar c
+and
+.No \e*( Ns Ar cc .
+.Ss \e-
+Special character
+.Dq mathematical minus sign .
+.Ss \e[ Ns Ar name ]
+.Sx Special Characters
+with names of arbitrary length, see
+.Xr mandoc_char 7 .
+.Ss \e^
+One-twelfth em half-narrow space character, effectively zero-width in
+.Xr mandoc 1 .
+.Ss \e`
+Grave accent special character; use
+.Sq \e(ga
+instead.
+.Ss \e{
+Begin conditional input; see
+.Sx if .
+.Ss \e\(ba
+One-sixth em narrow space character, effectively zero-width in
+.Xr mandoc 1 .
+.Ss \e}
+End conditional input; see
+.Sx if .
+.Ss \e~
+Paddable non-breaking space character.
+.Ss \e0
+Digit width space character.
+.Ss \eA\(aq Ns Ar string Ns \(aq
+Anchor definition; ignored by
+.Xr mandoc 1 .
+.Ss \eB\(aq Ns Ar string Ns \(aq
+Test whether
+.Ar string
+is a numerical expession; ignored by
+.Xr mandoc 1 .
+.Ss \eb\(aq Ns Ar string Ns \(aq
+Bracket building function; ignored by
+.Xr mandoc 1 .
+.Ss \eC\(aq Ns Ar name Ns \(aq
+.Sx Special Characters
+with names of arbitrary length.
+.Ss \ec
+Interrupt text processing to insert requests or macros; ignored by
+.Xr mandoc 1 .
+.Ss \eD\(aq Ns Ar string Ns \(aq
+Draw graphics function; ignored by
+.Xr mandoc 1 .
+.Ss \ed
+Move down by half a line; ignored by
+.Xr mandoc 1 .
+.Ss \ee
+Backslash special character.
+.Ss \eF[ Ns 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 .
+.Ss \ef[ Ns Ar name ]
+Switch to the font
+.Ar name ,
+see
+.Sx Text Decoration .
+For short names, there are variants
+.No \ef Ns Ar c
+and
+.No \ef( Ns Ar cc .
+.Ss \eg[ Ns Ar name ]
+Interpolate the format of a number register; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eg Ns Ar c
+and
+.No \eg( Ns Ar cc .
+.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 ]
+Mark horizontal input place in register; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \ek Ns Ar c
+and
+.No \ek( Ns Ar cc .
+.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 ]
+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 ]
+Set glyph drawing 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 \eN\(aq Ns Ar number Ns \(aq
+Character
+.Ar number
+on the current font.
+.Ss \en[ Ns 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 .
+.Ss \eo\(aq Ns Ar string Ns \(aq
+Overstrike
+.Ar string ;
+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 .
+.Ss \eS\(aq Ns Ar number Ns \(aq
+Slant output; ignored by
+.Xr mandoc 1 .
+.Ss \es\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
+Change point size; ignored by
+.Xr mandoc 1 .
+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 ] ,
+and
+.No \es Ns Oo +|- Oc Ns [ Ar number Ns ]
+are also parsed and ignored.
+.Ss \et
+Horizontal tab; ignored by
+.Xr mandoc 1 .
+.Ss \eu
+Move up by half a line; ignored by
+.Xr mandoc 1 .
+.Ss \eV[ Ns Ar name ]
+Interpolate an environment variable; ignored by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eV Ns Ar c
+and
+.No \eV( Ns Ar cc .
+.Ss \ev\(aq Ns Ar number Ns \(aq
+Vertical motion; ignored by
+.Xr mandoc 1 .
+.Ss \ew\(aq Ns Ar string Ns \(aq
+Interpolate the width of the
+.Ar string ;
+ignored by
+.Xr mandoc 1 .
+.Ss \eX\(aq Ns Ar string Ns \(aq
+Output
+.Ar string
+as device control function; ignored in nroff mode and 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 ]
+Output a string as a device control function; ignored in nroff mode and by
+.Xr mandoc 1 .
+For short names, there are variants
+.No \eY Ns Ar c
+and
+.No \eY( Ns Ar cc .
+.Ss \eZ\(aq Ns Ar string Ns \(aq
+Print
+.Ar string
+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.

 .Sh COMPATIBILITY
 .Sh COMPATIBILITY

-This section documents compatibility between mandoc and other other
-troff implementations, at this time limited to GNU troff
+This section documents compatibility between mandoc and other
+.Nm
+implementations, at this time limited to GNU troff

 .Pq Qq groff .
 The term
 .Qq historic groff
 .Pq Qq groff .
 The term
 .Qq historic groff

-refers to groff versions before the
-.Pa doc.tmac
-file re-write
-.Pq somewhere between 1.15 and 1.19 .
+refers to groff version 1.15.

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

-Historic groff did not accept white-space buffering the custom END tag
-for the
+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.
+.It
+The
+.Cm nS
+register is only compatible with OpenBSD's groff-1.15.
+.It
+Historic groff did not accept white-space before a custom
+.Ar end
+macro for the

 .Sx \&ig
 .Sx \&ig

-macro.
+request.

 .It
 The
 .Sx \&if
 and family would print funny white-spaces with historic groff when
 .It
 The
 .Sx \&if
 and family would print funny white-spaces with historic groff when

-depending on next-line syntax.
+using the next-line syntax.

 .El
 .El

+.Sh SEE ALSO
+.Xr mandoc 1 ,
+.Xr eqn 7 ,
+.Xr man 7 ,
+.Xr mandoc_char 7 ,
+.Xr mdoc 7 ,
+.Xr tbl 7
+.Rs
+.%A Joseph F. Ossanna
+.%A Brian W. Kernighan
+.%I AT&T Bell Laboratories
+.%T Troff User's Manual
+.%R Computing Science Technical Report
+.%N 54
+.%C Murray Hill, New Jersey
+.%D 1976 and 1992
+.%U http://www.kohala.com/start/troff/cstr54.ps
+.Re
+.Rs
+.%A Joseph F. Ossanna
+.%A Brian W. Kernighan
+.%A Gunnar Ritter
+.%T Heirloom Documentation Tools Nroff/Troff User's Manual
+.%D September 17, 2007
+.%U http://heirloom.sourceforge.net/doctools/troff.pdf
+.Re
+.Sh HISTORY
+The RUNOFF typesetting system, whose input forms the basis for
+.Nm ,
+was written in MAD and FAP for the CTSS operating system by Jerome E.
+Saltzer in 1964.
+Doug McIlroy rewrote it in BCPL in 1969, renaming it
+.Nm .
+Dennis M. Ritchie rewrote McIlroy's
+.Nm
+in PDP-11 assembly for
+.At v1 ,
+Joseph F. Ossanna improved roff and renamed it nroff
+for
+.At v2 ,
+then ported nroff to C as troff, which Brian W. Kernighan released with
+.At v7 .
+In 1989, James Clarke re-implemented troff in C++, naming it groff.

 .Sh AUTHORS
 .Sh AUTHORS

-The
+.An -nosplit
+This

 .Nm
 reference was written by
 .Nm
 reference was written by

-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
+and
+.An Ingo Schwarze Aq Mt schwarze@openbsd.org .