Implement the first steps of equation parsing from within libmdoc.

[mandoc.git] / man.7

diff --git a/man.7 b/man.7
index e5c47164e80e5b9cd8a28d1bbf9a9e486468ebb0..25e5e5bdeaf60976446a8d0b7fc3dec6049d439f 100644 (file)
--- a/man.7
+++ b/man.7
@@ -1,6 +1,6 @@
-.\"    $Id: man.7,v 1.21 2009/07/27 12:35:53 kristaps Exp $
+.\"    $Id: man.7,v 1.102 2011/07/08 09:35:06 kristaps Exp $

 .\"
 .\"

-.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>
+.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>

 .\"
 .\" 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


@@ -14,21 +14,19 @@
 .\" 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: July 27 2009 $
+.Dd $Mdocdate: July 8 2011 $

 .Dt MAN 7
 .Os
 .Dt MAN 7
 .Os

-.\" SECTION

 .Sh NAME
 .Nm man
 .Nd man language reference
 .Sh NAME
 .Nm man
 .Nd man language reference

-.\" SECTION

 .Sh DESCRIPTION
 The
 .Nm man
 language was historically used to format
 .Ux
 .Sh DESCRIPTION
 The
 .Nm man
 language was historically used to format
 .Ux

-manuals.  This reference document describes its syntax, structure, and
-usage.
+manuals.
+This reference document describes its syntax, structure, and usage.

 .Pp
 .Bf -emphasis
 Do not use
 .Pp
 .Bf -emphasis
 Do not use


@@ -38,45 +36,39 @@ to write your manuals.
 Use the
 .Xr mdoc 7
 language, instead.
 Use the
 .Xr mdoc 7
 language, instead.

-.\" PARAGRAPH

 .Pp
 .Pp

-An
+A

 .Nm
 document follows simple rules:  lines beginning with the control
 character
 .Sq \&.
 .Nm
 document follows simple rules:  lines beginning with the control
 character
 .Sq \&.

-are parsed for macros.  Other lines are interpreted within the scope of
+are parsed for macros.
+Other lines are interpreted within the scope of

 prior macros:
 .Bd -literal -offset indent
 \&.SH Macro lines change control state.
 Other lines are interpreted within the current state.
 .Ed
 prior macros:
 .Bd -literal -offset indent
 \&.SH Macro lines change control state.
 Other lines are interpreted within the current state.
 .Ed

-.\" SECTION

 .Sh INPUT ENCODING
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the
 .Sh INPUT ENCODING
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the

-space character, and the tabs character.  All manuals must have
-.Ux
-line termination.
+space character, and the tab character.

 .Pp
 Blank lines are acceptable; where found, the output will assert a
 vertical space.
 .Pp
 .Pp
 Blank lines are acceptable; where found, the output will assert a
 vertical space.
 .Pp

-The
-.Sq \ec
-escape is common in historical
-.Nm
-documents; if encountered at the end of a word, it ensures that the
-subsequent word isn't off-set by whitespace.
-.\" SUB-SECTION
+If the first character of a line is a space, that line is printed
+with a leading newline.

 .Ss Comments
 Text following a
 .Ss Comments
 Text following a

-.Sq \e" ,
+.Sq \e\*q ,

 whether in a macro or free-form text line, is ignored to the end of
 whether in a macro or free-form text line, is ignored to the end of

-line.  A macro line with only a control character and comment escape,
-.Sq \&.\e" ,
+line.
+A macro line with only a control character and comment escape,
+.Sq \&.\e\*q ,

 is also ignored.
 is also ignored.

-.\" SUB-SECTION
+Macro lines with only a control character and optionally whitespace are
+stripped from input.

 .Ss Special Characters
 Special characters may occur in both macro and free-form lines.
 Sequences begin with the escape character
 .Ss Special Characters
 Special characters may occur in both macro and free-form lines.
 Sequences begin with the escape character


@@ -87,158 +79,872 @@ for two-character sequences; an open-bracket
 .Sq \&[
 for n-character sequences (terminated at a close-bracket
 .Sq \&] ) ;
 .Sq \&[
 for n-character sequences (terminated at a close-bracket
 .Sq \&] ) ;

-or a single one-character sequence.  See
+or a single one-character sequence.
+See

 .Xr mandoc_char 7
 .Xr mandoc_char 7

-for a complete list.  Examples include
+for a complete list.
+Examples include

 .Sq \e(em
 .Pq em-dash
 and
 .Sq \ee
 .Pq back-slash .
 .Sq \e(em
 .Pq em-dash
 and
 .Sq \ee
 .Pq back-slash .

-.\" SUB-SECTION----------------------

 .Ss Text Decoration
 Terms may be text-decorated using the
 .Sq \ef
 .Ss Text Decoration
 Terms may be text-decorated using the
 .Sq \ef

-escape followed by an indicator: B (bold), I, (italic), or P and R
-(Roman, or reset).
-.\" SUB-SECTION----------------------
+escape followed by an indicator: B (bold), I (italic), R (Roman), or P
+(revert to previous mode):
+.Pp
+.D1 \efBbold\efR \efIitalic\efP
+.Pp
+A numerical representation 3, 2, or 1 (bold, italic, and Roman,
+respectively) may be used instead.
+A text decoration is only valid, if specified in free-form text, until
+the next macro invocation; if specified within a macro, it's only valid
+until the macro closes scope.
+Note that macros like
+.Sx \&BR
+open and close a font scope with each argument.
+.Pp
+The
+.Sq \ef
+attribute is forgotten when entering or exiting a macro block.

 .Ss Whitespace
 .Ss Whitespace

-Unless specifically escaped, consecutive blocks of whitespace are pruned
-from input.  These are later re-added, if applicable, by a front-end
-utility such as
-.Xr mandoc 1 .
-.\" SECTION
-.Sh STRUCTURE
+Whitespace consists of the space character.
+In free-form lines, whitespace is preserved within a line; unescaped
+trailing spaces are stripped from input (unless in a literal context).
+Blank free-form lines, which may include spaces, are permitted and
+rendered as an empty line.
+.Pp
+In macro lines, whitespace delimits arguments and is discarded.
+If arguments are quoted, whitespace within the quotes is retained.
+.Ss Scaling Widths
+Many macros support scaled widths for their arguments, such as
+stipulating a two-inch paragraph indentation with the following:
+.Bd -literal -offset indent
+\&.HP 2i
+.Ed
+.Pp
+The syntax for scaled widths is
+.Sq Li [+-]?[0-9]*.[0-9]*[:unit:]? ,
+where a decimal must be preceded or proceeded by at least one digit.
+Negative numbers, while accepted, are truncated to zero.
+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.
+.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.
+.Em Note :
+this differs from
+.Xr mdoc 7 ,
+which, if a unit is not provided, will instead interpret the string as
+literal text.
+.Ss Sentence Spacing
+When composing a manual, make sure that sentences end at the end of
+a line.
+By doing so, front-ends 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 .
+.Sh MANUAL STRUCTURE

 Each
 .Nm
 Each
 .Nm

-document must contain contains at least the
-.Sq \&.TH
-macro describing the document's section and title.  It may occur
-anywhere in the document, although conventionally, it appears as the
-first macro.
-.Pp
-Beyond the
-.Sq \&.TH ,
+document must contain the
+.Sx \&TH
+macro describing the document's section and title.
+It may occur anywhere in the document, although conventionally it
+appears as the first macro.
+.Pp
+Beyond
+.Sx \&TH ,

 at least one macro or text node must appear in the document.
 at least one macro or text node must appear in the document.

-.\" SECTION
-.Sh SYNTAX
-Macros are one to three three characters in length and begin with a
-control character ,
-.Sq \&. ,
-at the beginning of the line.  An arbitrary amount of whitespace may
-sit between the control character and the macro name.  Thus,
-.Sq \&.PP
-and
-.Sq \&.\ \ \ \&PP
-are equivalent.

 .Pp
 .Pp

-All
+The following is a well-formed skeleton

 .Nm
 .Nm

-macros follow the same structural rules:
+file for a utility
+.Qq progname :

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

-\&.YO \(lBbody...\(rB
+\&.TH PROGNAME 1 2009-10-10
+\&.SH NAME
+\efBprogname\efR \e(en a description goes here
+\&.\e\*q .SH LIBRARY
+\&.\e\*q For sections 2 & 3 only.
+\&.\e\*q Not used in OpenBSD.
+\&.SH SYNOPSIS
+\efBprogname\efR [\efB\e-options\efR] arguments...
+\&.SH DESCRIPTION
+The \efBfoo\efR utility processes files...
+\&.\e\*q .SH IMPLEMENTATION NOTES
+\&.\e\*q Not used in OpenBSD.
+\&.\e\*q .SH RETURN VALUES
+\&.\e\*q For sections 2, 3, & 9 only.
+\&.\e\*q .SH ENVIRONMENT
+\&.\e\*q For sections 1, 6, 7, & 8 only.
+\&.\e\*q .SH FILES
+\&.\e\*q .SH EXIT STATUS
+\&.\e\*q For sections 1, 6, & 8 only.
+\&.\e\*q .SH EXAMPLES
+\&.\e\*q .SH DIAGNOSTICS
+\&.\e\*q For sections 1, 4, 6, 7, & 8 only.
+\&.\e\*q .SH ERRORS
+\&.\e\*q For sections 2, 3, & 9 only.
+\&.\e\*q .SH SEE ALSO
+\&.\e\*q .BR foo ( 1 )
+\&.\e\*q .SH STANDARDS
+\&.\e\*q .SH HISTORY
+\&.\e\*q .SH AUTHORS
+\&.\e\*q .SH CAVEATS
+\&.\e\*q .SH BUGS
+\&.\e\*q .SH SECURITY CONSIDERATIONS
+\&.\e\*q Not used in OpenBSD.

 .Ed
 .Pp
 .Ed
 .Pp

+The sections in a
+.Nm
+document are conventionally ordered as they appear above.
+Sections should be composed as follows:
+.Bl -ohang -offset indent
+.It Em NAME
+The name(s) and a short description of the documented material.
+The syntax for this is generally as follows:
+.Pp
+.D1 \efBname\efR \e(en description
+.It Em LIBRARY
+The name of the library containing the documented material, which is
+assumed to be a function in a section 2 or 3 manual.
+For functions in the C library, this may be as follows:
+.Pp
+.D1 Standard C Library (libc, -lc)
+.It Em SYNOPSIS
+Documents the utility invocation syntax, function call syntax, or device
+configuration.
+.Pp
+For the first, utilities (sections 1, 6, and 8), this is
+generally structured as follows:
+.Pp
+.D1 \efBname\efR [-\efBab\efR] [-\efBc\efR\efIarg\efR] \efBpath\efR...
+.Pp
+For the second, function calls (sections 2, 3, 9):
+.Pp
+.D1 \&.B char *name(char *\efIarg\efR);
+.Pp
+And for the third, configurations (section 4):
+.Pp
+.D1 \&.B name* at cardbus ? function ?
+.Pp
+Manuals not in these sections generally don't need a
+.Em SYNOPSIS .
+.It Em DESCRIPTION
+This expands upon the brief, one-line description in
+.Em NAME .
+It usually contains a break-down of the options (if documenting a
+command).
+.It Em IMPLEMENTATION NOTES
+Implementation-specific notes should be kept here.
+This is useful when implementing standard functions that may have side
+effects or notable algorithmic implications.
+.It Em RETURN VALUES
+This section documents the return values of functions in sections 2, 3, and 9.
+.It Em ENVIRONMENT
+Documents any usages of environment variables, e.g.,
+.Xr environ 7 .
+.It Em FILES
+Documents files used.
+It's helpful to document both the file name and a short description of how
+the file is used (created, modified, etc.).
+.It Em EXIT STATUS
+This section documents the command exit status for
+section 1, 6, and 8 utilities.
+Historically, this information was described in
+.Em DIAGNOSTICS ,
+a practise that is now discouraged.
+.It Em EXAMPLES
+Example usages.
+This often contains snippets of well-formed,
+well-tested invocations.
+Make sure that examples work properly!
+.It Em DIAGNOSTICS
+Documents error conditions.
+This is most useful in section 4 manuals.
+Historically, this section was used in place of
+.Em EXIT STATUS
+for manuals in sections 1, 6, and 8; however, this practise is
+discouraged.
+.It Em ERRORS
+Documents error handling in sections 2, 3, and 9.
+.It Em SEE ALSO
+References other manuals with related topics.
+This section should exist for most manuals.
+.Pp
+.D1 \&.BR bar \&( 1 \&),
+.Pp
+Cross-references should conventionally be ordered
+first by section, then alphabetically.
+.It Em STANDARDS
+References any standards implemented or used, such as
+.Pp
+.D1 IEEE Std 1003.2 (\e(lqPOSIX.2\e(rq)
+.Pp
+If not adhering to any standards, the
+.Em HISTORY
+section should be used.
+.It Em HISTORY
+A brief history of the subject, including where support first appeared.
+.It Em AUTHORS
+Credits to the person or persons who wrote the code and/or documentation.
+Authors should generally be noted by both name and email address.
+.It Em CAVEATS
+Common misuses and misunderstandings should be explained
+in this section.
+.It Em BUGS
+Known bugs, limitations, and work-arounds should be described
+in this section.
+.It Em SECURITY CONSIDERATIONS
+Documents any security precautions that operators should consider.
+.El
+.Sh MACRO SYNTAX
+Macros are one to three characters in length and begin with a
+control character,
+.Sq \&. ,
+at the beginning of the line.

 The
 The

-.Dq body
-consists of zero or more arguments to the macro.
+.Sq \(aq
+macro control character is also accepted.
+An arbitrary amount of whitespace (spaces or tabs) may sit between the
+control character and the macro name.
+Thus, the following are equivalent:
+.Bd -literal -offset indent
+\&.PP
+\&.\ \ \ PP
+.Ed

 .Pp
 .Pp

+To include space characters in macro arguments, arguments may be quoted;
+see the
+.Sq MACRO SYNTAX
+section in the
+.Xr roff 7
+manual for details.
+.Pp
+The

 .Nm
 .Nm

-has a primitive notion of multi-line scope for the following macros:
-.Sq \&.TM ,
-.Sq \&.SM ,
-.Sq \&.SB ,
-.Sq \&.BI ,
-.Sq \&.IB ,
-.Sq \&.BR ,
-.Sq \&.RB ,
-.Sq \&.R ,
-.Sq \&.B ,
-.Sq \&.I ,
-.Sq \&.IR
-and
-.Sq \&.RI .
-When these macros are invoked without arguments, the subsequent line is
-considered a continuation of the macro.  Thus:
+macros are classified by scope: line scope or block scope.
+Line macros are only scoped to the current line (and, in some
+situations, the subsequent line).
+Block macros are scoped to the current line and subsequent lines until
+closed by another block macro.
+.Ss Line Macros
+Line macros are generally scoped to the current line, with the body
+consisting of zero or more arguments.
+If a macro is scoped to the next line and the line arguments are empty,
+the next line, which must be text, is used instead.
+Thus:

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

-\&.RI
+\&.I

 foo
 .Ed
 .Pp
 is equivalent to
 foo
 .Ed
 .Pp
 is equivalent to

-.Sq \&.RI foo .
-If two consecutive lines exhibit the latter behaviour,
-an error is raised.  Thus, the following is not acceptable:
+.Sq \&.I foo .
+If next-line macros are invoked consecutively, only the last is used.
+If a next-line macro is followed by a non-next-line macro, an error is
+raised, except for
+.Sx \&br ,
+.Sx \&sp ,
+and
+.Sx \&na .
+.Pp
+The syntax is as follows:

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

-\&.RI
-\&.I
-Hello, world.
+\&.YO \(lBbody...\(rB
+\(lBbody...\(rB

 .Ed
 .Pp
 .Ed
 .Pp

-The
-.Sq \&.TP
-macro is similar, but does not need an empty argument line to trigger
-the behaviour.
-.\" SECTION
-.Sh MACROS
-This section contains a complete list of all
-.Nm
-macros and corresponding number of arguments.
-.Pp
-.Bl -column "MacroX" "Arguments" -compact -offset indent
-.It Em Macro Ta Em Arguments
-.It \&.TH    Ta    >1, <6
-.It \&.SH    Ta    >0
-.It \&.SS    Ta    >0
-.It \&.TP    Ta    n
-.It \&.LP    Ta    0
-.It \&.PP    Ta    0
-.It \&.P     Ta    0
-.It \&.IP    Ta    <3
-.It \&.HP    Ta    <2
-.It \&.SM    Ta    n
-.It \&.SB    Ta    n
-.It \&.BI    Ta    n
-.It \&.IB    Ta    n
-.It \&.BR    Ta    n
-.It \&.RB    Ta    n
-.It \&.R     Ta    n
-.It \&.B     Ta    n
-.It \&.I     Ta    n
-.It \&.IR    Ta    n
-.It \&.RI    Ta    n
+.Bl -column -compact -offset indent "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX"
+.It Em Macro Ta Em Arguments Ta Em Scope     Ta Em Notes
+.It Sx \&AT  Ta    <=1       Ta    current   Ta    \&
+.It Sx \&B   Ta    n         Ta    next-line Ta    \&
+.It Sx \&BI  Ta    n         Ta    current   Ta    \&
+.It Sx \&BR  Ta    n         Ta    current   Ta    \&
+.It Sx \&DT  Ta    0         Ta    current   Ta    \&
+.It Sx \&I   Ta    n         Ta    next-line Ta    \&
+.It Sx \&IB  Ta    n         Ta    current   Ta    \&
+.It Sx \&IR  Ta    n         Ta    current   Ta    \&
+.It Sx \&R   Ta    n         Ta    next-line Ta    \&
+.It Sx \&RB  Ta    n         Ta    current   Ta    \&
+.It Sx \&RI  Ta    n         Ta    current   Ta    \&
+.It Sx \&SB  Ta    n         Ta    next-line Ta    \&
+.It Sx \&SM  Ta    n         Ta    next-line Ta    \&
+.It Sx \&TH  Ta    >1, <6    Ta    current   Ta    \&
+.It Sx \&UC  Ta    <=1       Ta    current   Ta    \&
+.It Sx \&br  Ta    0         Ta    current   Ta    compat
+.It Sx \&fi  Ta    0         Ta    current   Ta    compat
+.It Sx \&ft  Ta    1         Ta    current   Ta    compat
+.It Sx \&in  Ta    1         Ta    current   Ta    compat
+.It Sx \&na  Ta    0         Ta    current   Ta    compat
+.It Sx \&nf  Ta    0         Ta    current   Ta    compat
+.It Sx \&sp  Ta    1         Ta    current   Ta    compat

 .El
 .Pp
 .El
 .Pp

-Although not historically part of the
+Macros marked as
+.Qq compat
+are included for compatibility with the significant corpus of existing
+manuals that mix dialects of roff.
+These macros should not be used for portable

 .Nm
 .Nm

-system, the following macros are also supported:
+manuals.
+.Ss Block Macros
+Block macros comprise a head and body.
+As with in-line macros, the head is scoped to the current line and, in
+one circumstance, the next line (the next-line stipulations as in
+.Sx Line Macros
+apply here as well).
+.Pp
+The syntax is as follows:
+.Bd -literal -offset indent
+\&.YO \(lBhead...\(rB
+\(lBhead...\(rB
+\(lBbody...\(rB
+.Ed
+.Pp
+The closure of body scope may be to the section, where a macro is closed
+by
+.Sx \&SH ;
+sub-section, closed by a section or
+.Sx \&SS ;
+part, closed by a section, sub-section, or
+.Sx \&RE ;
+or paragraph, closed by a section, sub-section, part,
+.Sx \&HP ,
+.Sx \&IP ,
+.Sx \&LP ,
+.Sx \&P ,
+.Sx \&PP ,
+or
+.Sx \&TP .
+No closure refers to an explicit block closing macro.

 .Pp
 .Pp

-.Bl -column "MacroX" "Arguments" -compact -offset indent
-.It Em Macro Ta Em Arguments
-.It \&.br    Ta    0
-.It \&.i     Ta    n
+As a rule, block macros may not be nested; thus, calling a block macro
+while another block macro scope is open, and the open scope is not
+implicitly closed, is syntactically incorrect.
+.Pp
+.Bl -column -compact -offset indent "MacroX" "ArgumentsX" "Head ScopeX" "sub-sectionX" "compatX"
+.It Em Macro Ta Em Arguments Ta Em Head Scope Ta Em Body Scope  Ta Em Notes
+.It Sx \&HP  Ta    <2        Ta    current    Ta    paragraph   Ta    \&
+.It Sx \&IP  Ta    <3        Ta    current    Ta    paragraph   Ta    \&
+.It Sx \&LP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
+.It Sx \&P   Ta    0         Ta    current    Ta    paragraph   Ta    \&
+.It Sx \&PP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
+.It Sx \&RE  Ta    0         Ta    current    Ta    none        Ta    compat
+.It Sx \&RS  Ta    1         Ta    current    Ta    part        Ta    compat
+.It Sx \&SH  Ta    >0        Ta    next-line  Ta    section     Ta    \&
+.It Sx \&SS  Ta    >0        Ta    next-line  Ta    sub-section Ta    \&
+.It Sx \&TP  Ta    n         Ta    next-line  Ta    paragraph   Ta    \&

 .El
 .Pp
 .El
 .Pp

-These follow the same calling conventions as the above
-.Nm
-macros.
-.\" SECTION
-.Sh COMPATIBILITY
+Macros marked
+.Qq compat
+are as mentioned in
+.Sx Line Macros .
+.Pp
+If a block macro is next-line scoped, it may only be followed by in-line
+macros for decorating text.
+.Sh REFERENCE
+This section is a canonical reference to all macros, arranged
+alphabetically.
+For the scoping of individual macros, see
+.Sx MACRO SYNTAX .
+.Ss \&AT
+Sets the volume for the footer for compatibility with man pages from
+.Tn AT&T UNIX
+releases.
+The optional arguments specify which release it is from.
+.Ss \&B
+Text is rendered in bold face.
+.Pp
+See also
+.Sx \&I
+and
+.Sx \&R .
+.Ss \&BI
+Text is rendered alternately in bold face and italic.
+Thus,
+.Sq .BI this word and that
+causes
+.Sq this
+and
+.Sq and
+to render in bold face, while
+.Sq word
+and
+.Sq that
+render in italics.
+Whitespace between arguments is omitted in output.
+.Pp
+Examples:
+.Pp
+.Dl \&.BI bold italic bold italic
+.Pp
+The output of this example will be emboldened
+.Dq bold
+and italicised
+.Dq italic ,
+with spaces stripped between arguments.
+.Pp
+See also
+.Sx \&IB ,
+.Sx \&BR ,
+.Sx \&RB ,
+.Sx \&RI ,
+and
+.Sx \&IR .
+.Ss \&BR
+Text is rendered alternately in bold face and roman (the default font).
+Whitespace between arguments is omitted in output.
+.Pp

 See
 See

-.Xr mdoc 7
-for groff compatibility notes.
-.\" SECTION
+.Sx \&BI
+for an equivalent example.
+.Pp
+See also
+.Sx \&BI ,
+.Sx \&IB ,
+.Sx \&RB ,
+.Sx \&RI ,
+and
+.Sx \&IR .
+.Ss \&DT
+Has no effect.
+Included for compatibility.
+.Ss \&HP
+Begin a paragraph whose initial output line is left-justified, but
+subsequent output lines are indented, with the following syntax:
+.Bd -filled -offset indent
+.Pf \. Sx \&HP
+.Op Cm width
+.Ed
+.Pp
+The
+.Cm width
+argument must conform to
+.Sx Scaling Widths .
+If specified, it's saved for later paragraph left-margins; if unspecified, the
+saved or default width is used.
+.Pp
+See also
+.Sx \&IP ,
+.Sx \&LP ,
+.Sx \&P ,
+.Sx \&PP ,
+and
+.Sx \&TP .
+.Ss \&I
+Text is rendered in italics.
+.Pp
+See also
+.Sx \&B
+and
+.Sx \&R .
+.Ss \&IB
+Text is rendered alternately in italics and bold face.
+Whitespace between arguments is omitted in output.
+.Pp
+See
+.Sx \&BI
+for an equivalent example.
+.Pp
+See also
+.Sx \&BI ,
+.Sx \&BR ,
+.Sx \&RB ,
+.Sx \&RI ,
+and
+.Sx \&IR .
+.Ss \&IP
+Begin an indented paragraph with the following syntax:
+.Bd -filled -offset indent
+.Pf \. Sx \&IP
+.Op Cm head Op Cm width
+.Ed
+.Pp
+The
+.Cm width
+argument defines the width of the left margin and is defined by
+.Sx Scaling Widths .
+It's saved for later paragraph left-margins; if unspecified, the saved or
+default width is used.
+.Pp
+The
+.Cm head
+argument is used as a leading term, flushed to the left margin.
+This is useful for bulleted paragraphs and so on.
+.Pp
+See also
+.Sx \&HP ,
+.Sx \&LP ,
+.Sx \&P ,
+.Sx \&PP ,
+and
+.Sx \&TP .
+.Ss \&IR
+Text is rendered alternately in italics and roman (the default font).
+Whitespace between arguments is omitted in output.
+.Pp
+See
+.Sx \&BI
+for an equivalent example.
+.Pp
+See also
+.Sx \&BI ,
+.Sx \&IB ,
+.Sx \&BR ,
+.Sx \&RB ,
+and
+.Sx \&RI .
+.Ss \&LP
+Begin an undecorated paragraph.
+The scope of a paragraph is closed by a subsequent paragraph,
+sub-section, section, or end of file.
+The saved paragraph left-margin width is reset to the default.
+.Pp
+See also
+.Sx \&HP ,
+.Sx \&IP ,
+.Sx \&P ,
+.Sx \&PP ,
+and
+.Sx \&TP .
+.Ss \&P
+Synonym for
+.Sx \&LP .
+.Pp
+See also
+.Sx \&HP ,
+.Sx \&IP ,
+.Sx \&LP ,
+.Sx \&PP ,
+and
+.Sx \&TP .
+.Ss \&PP
+Synonym for
+.Sx \&LP .
+.Pp
+See also
+.Sx \&HP ,
+.Sx \&IP ,
+.Sx \&LP ,
+.Sx \&P ,
+and
+.Sx \&TP .
+.Ss \&R
+Text is rendered in roman (the default font).
+.Pp
+See also
+.Sx \&I
+and
+.Sx \&B .
+.Ss \&RB
+Text is rendered alternately in roman (the default font) and bold face.
+Whitespace between arguments is omitted in output.
+.Pp
+See
+.Sx \&BI
+for an equivalent example.
+.Pp
+See also
+.Sx \&BI ,
+.Sx \&IB ,
+.Sx \&BR ,
+.Sx \&RI ,
+and
+.Sx \&IR .
+.Ss \&RE
+Explicitly close out the scope of a prior
+.Sx \&RS .
+The default left margin is restored to the state of the original
+.Sx \&RS
+invocation.
+.Ss \&RI
+Text is rendered alternately in roman (the default font) and italics.
+Whitespace between arguments is omitted in output.
+.Pp
+See
+.Sx \&BI
+for an equivalent example.
+.Pp
+See also
+.Sx \&BI ,
+.Sx \&IB ,
+.Sx \&BR ,
+.Sx \&RB ,
+and
+.Sx \&IR .
+.Ss \&RS
+Temporarily reset the default left margin.
+This has the following syntax:
+.Bd -filled -offset indent
+.Pf \. Sx \&RS
+.Op Cm width
+.Ed
+.Pp
+The
+.Cm width
+argument must conform to
+.Sx Scaling Widths .
+If not specified, the saved or default width is used.
+.Pp
+See also
+.Sx \&RE .
+.Ss \&SB
+Text is rendered in small size (one point smaller than the default font)
+bold face.
+.Ss \&SH
+Begin a section.
+The scope of a section is only closed by another section or the end of
+file.
+The paragraph left-margin width is reset to the default.
+.Ss \&SM
+Text is rendered in small size (one point smaller than the default
+font).
+.Ss \&SS
+Begin a sub-section.
+The scope of a sub-section is closed by a subsequent sub-section,
+section, or end of file.
+The paragraph left-margin width is reset to the default.
+.Ss \&TH
+Sets the title of the manual page with the following syntax:
+.Bd -filled -offset indent
+.Pf \. Sx \&TH
+.Ar title section date
+.Op Ar source Op Ar volume
+.Ed
+.Pp
+Conventionally, the document
+.Ar title
+is given in all caps.
+The recommended
+.Ar date
+format is
+.Sy YYYY-MM-DD
+as specified in the ISO-8601 standard;
+if the argument does not conform, it is printed verbatim.
+If the
+.Ar date
+is empty or not specified, the current date is used.
+The optional
+.Ar source
+string specifies the organisation providing the utility.
+The
+.Ar volume
+string replaces the default rendered volume, which is dictated by the
+manual section.
+.Pp
+Examples:
+.Pp
+.Dl \&.TH CVS 5 "1992-02-12" GNU
+.Ss \&TP
+Begin a paragraph where the head, if exceeding the indentation width, is
+followed by a newline; if not, the body follows on the same line after a
+buffer to the indentation width.
+Subsequent output lines are indented.
+The syntax is as follows:
+.Bd -filled -offset indent
+.Pf \. Sx \&TP
+.Op Cm width
+.Ed
+.Pp
+The
+.Cm width
+argument must conform to
+.Sx Scaling Widths .
+If specified, it's saved for later paragraph left-margins; if
+unspecified, the saved or default width is used.
+.Pp
+See also
+.Sx \&HP ,
+.Sx \&IP ,
+.Sx \&LP ,
+.Sx \&P ,
+and
+.Sx \&PP .
+.Ss \&UC
+Sets the volume for the footer for compatibility with man pages from
+BSD releases.
+The optional first argument specifies which release it is from.
+.Ss \&br
+Breaks the current line.
+Consecutive invocations have no further effect.
+.Pp
+See also
+.Sx \&sp .
+.Ss \&fi
+End literal mode begun by
+.Sx \&nf .
+.Ss \&ft
+Change the current font mode.
+See
+.Sx Text Decoration
+for a listing of available font modes.
+.Ss \&in
+Indent relative to the current indentation:
+.Pp
+.D1 Pf \. Sx \&in Op Cm width
+.Pp
+If
+.Cm width
+is signed, the new offset is relative.
+Otherwise, it is absolute.
+This value is reset upon the next paragraph, section, or sub-section.
+.Ss \&na
+Don't align to the right margin.
+.Ss \&nf
+Begin literal mode: all subsequent free-form lines have their end of
+line boundaries preserved.
+May be ended by
+.Sx \&fi .
+Literal mode is implicitly ended by
+.Sx \&SH
+or
+.Sx \&SS .
+.Ss \&sp
+Insert vertical spaces into output with the following syntax:
+.Bd -filled -offset indent
+.Pf \. Sx \&sp
+.Op Cm height
+.Ed
+.Pp
+Insert
+.Cm height
+spaces, which must conform to
+.Sx Scaling Widths .
+If 0, this is equivalent to the
+.Sx \&br
+macro.
+Defaults to 1, if unspecified.
+.Pp
+See also
+.Sx \&br .
+.Sh COMPATIBILITY
+This section documents areas of questionable portability between
+implementations of the
+.Nm
+language.
+.Pp
+.Bl -dash -compact
+.It
+In quoted literals, GNU troff allowed pair-wise double-quotes to produce
+a standalone double-quote in formatted output.
+It is not known whether this behaviour is exhibited by other formatters.
+.It
+troff suppresses a newline before
+.Sq \(aq
+macro output; in mandoc, it is an alias for the standard
+.Sq \&.
+control character.
+.It
+The
+.Sq \eh
+.Pq horizontal position ,
+.Sq \ev
+.Pq vertical position ,
+.Sq \em
+.Pq text colour ,
+.Sq \eM
+.Pq text filling colour ,
+.Sq \ez
+.Pq zero-length character ,
+.Sq \ew
+.Pq string length ,
+.Sq \ek
+.Pq horizontal position marker ,
+.Sq \eo
+.Pq text overstrike ,
+and
+.Sq \es
+.Pq text size
+escape sequences are all discarded in mandoc.
+.It
+The
+.Sq \ef
+scaling unit is accepted by mandoc, but rendered as the default unit.
+.It
+The
+.Sx \&sp
+macro does not accept negative values in mandoc.
+In GNU troff, this would result in strange behaviour.
+.El

 .Sh SEE ALSO
 .Sh SEE ALSO

+.Xr man 1 ,

 .Xr mandoc 1 ,
 .Xr mandoc 1 ,

-.Xr mandoc_char 7
-.\" SECTION
-.Sh AUTHORS
+.Xr eqn 7 ,
+.Xr mandoc_char 7 ,
+.Xr mdoc 7 ,
+.Xr roff 7 ,
+.Xr tbl 7
+.Sh HISTORY

 The
 .Nm
 The
 .Nm

-utility was written by
-.An Kristaps Dzonsons Aq kristaps@kth.se .
-.\" SECTION
+language first appeared as a macro package for the roff typesetting
+system in
+.At v7 .
+It was later rewritten by James Clark as a macro package for groff.
+The stand-alone implementation that is part of the
+.Xr mandoc 1
+utility written by Kristaps Dzonsons appeared in
+.Ox 4.6 .
+.Sh AUTHORS
+This
+.Nm
+reference was written by
+.An Kristaps Dzonsons Aq kristaps@bsd.lv .

 .Sh CAVEATS
 .Sh CAVEATS

-Do not use this language.  Use
+Do not use this language.
+Use

 .Xr mdoc 7 ,
 instead.
 .Xr mdoc 7 ,
 instead.