-.\" $Id: mdoc.7,v 1.105 2010/05/14 16:02:29 kristaps Exp $
+.\" $Id: mdoc.7,v 1.202 2011/08/18 08:58:44 kristaps Exp $
.\"
-.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2010 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
.\" 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 14 2010 $
+.Dd $Mdocdate: August 18 2011 $
.Dt MDOC 7
.Os
.Sh NAME
language is used to format
.Bx
.Ux
-manuals. In this reference document, we describe its syntax, structure,
-and usage. Our reference implementation is mandoc; the
+manuals.
+This reference document describes its syntax, structure, and
+usage.
+The reference implementation for
+.Nm
+formatting is
+.Xr mandoc 1 ;
+the
.Sx COMPATIBILITY
-section describes compatibility with other troff \-mdoc implementations.
+section describes compatibility with other implementations.
.Pp
An
.Nm
-document follows simple rules: lines beginning with the control
+document follows simple rules: lines beginning with the control
character
-.Sq \.
-are parsed for macros. Other lines are interpreted within the scope of
-prior macros:
+.Sq \&.
+are parsed for macros.
+Lines not beginning with the control character 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.
+Text lines are interpreted within the current state.
.Ed
.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.
+character, and, in certain circumstances, the tab character.
+The back-space character
+.Sq \e
+indicates the start of an escape sequence for
+.Sx Comments ,
+.Sx Predefined Strings ,
+and
+.Sx Special Characters .
.Ss Comments
-Text following a
-.Sq \e" ,
-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" ,
-is also ignored. Macro lines with only a control charater and optionally
-whitespace are stripped from input.
-.Ss Reserved Characters
-Within a macro line, the following characters are reserved:
-.Pp
-.Bl -tag -width Ds -offset indent -compact
-.It \&.
-.Pq period
-.It \&,
-.Pq comma
-.It \&:
-.Pq colon
-.It \&;
-.Pq semicolon
-.It \&(
-.Pq left-parenthesis
-.It \&)
-.Pq right-parenthesis
-.It \&[
-.Pq left-bracket
-.It \&]
-.Pq right-bracket
-.It \&?
-.Pq question
-.It \&!
-.Pq exclamation
-.It \&|
-.Pq vertical bar
-.El
+Text following an escaped double-quote
+.Sq \e\*q ,
+whether in a macro or text line, is ignored to the end of
+line.
+A macro line beginning with a control character and comment escape
+.Sq \&.\e\*q
+is also ignored.
+Furthermore,
+macro lines with only a control character and optional trailing
+whitespace are
+stripped from input.
.Pp
-Use of reserved characters is described in
-.Sx MACRO SYNTAX .
-For general use in macro lines, these characters must either be escaped
-with a non-breaking space
-.Pq Sq \e&
-or, if applicable, an appropriate escape sequence used.
+Examples:
+.Bd -literal -offset indent -compact
+\&.\e\*q This is a comment line.
+\&.\e\*q The next line is ignored:
+\&.
+\&.Em Emphasis \e\*q This is also a comment.
+.Ed
.Ss Special Characters
-Special characters may occur in both macro and free-form lines.
+Special characters are used to encode special glyphs and are rendered
+differently across output media.
+They may occur in both macro and text lines.
Sequences begin with the escape character
.Sq \e
followed by either an open-parenthesis
.Sq \&[
for n-character sequences (terminated at a close-bracket
.Sq \&] ) ;
-or a single one-character sequence.
+or a single one character sequence.
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \e(em
+em dash
+.It \ee
+backslash
+.El
+.Pp
See
.Xr mandoc_char 7
for a complete list.
-Examples include
-.Sq \e(em
-.Pq em-dash
-and
-.Sq \ee
-.Pq back-slash .
.Ss Text Decoration
Terms may be text-decorated using the
.Sq \ef
-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,
+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.
-A text decoration is valid within
-the current font scope only: if a macro opens a font scope alongside
-its own scope, such as
-.Sx \&Bf
-.Cm \&Sy ,
-in-scope invocations of
-.Sq \ef
-are only valid within the font scope of the macro.
-If
+If a macro opens a font scope after calling
+.Sq \ef ,
+such as with
+.Sx \&Bf ,
+the
.Sq \ef
-is specified outside of any font scope, such as in unenclosed, free-form
-text, it will affect the remainder of the document.
-.Pp
-Text may also be sized with the
-.Sq \es
-escape, whose syntax is one of
-.Sq \es+-n
-for one-digit numerals;
-.Sq \es(+-nn
-or
-.Sq \es+-(nn
-for two-digit numerals; and
-.Sq \es[+-N] ,
-.Sq \es+-[N] ,
-.Sq \es'+-N' ,
-or
-.Sq \es+-'N'
-for arbitrary-digit numerals:
+mode will be restored upon exiting the
+.Sx \&Bf
+scope.
.Pp
-.D1 \es+1bigger\es-1
-.D1 \es[+10]much bigger\es[-10]
-.D1 \es+(10much bigger\es-(10
-.D1 \es+'100'much much bigger\es-'100'
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \efBbold\efR
+write in bold, then switch to regular
+.It \efIitalic\efP
+write in italic, then return to previous
+.El
.Pp
-Note these forms are
+Text decoration is
.Em not
recommended for
.Nm ,
which encourages semantic annotation.
.Ss Predefined Strings
-Historically,
-.Xr groff 1
-also defined a set of package-specific
-.Dq predefined strings ,
-which, like
+Predefined strings, like
.Sx Special Characters ,
-demark special output characters and strings by way of input codes.
+mark special output glyphs.
Predefined strings are escaped with the slash-asterisk,
.Sq \e* :
single-character
.Sq \e*(XX ,
and N-character
.Sq \e*[N] .
-See
-.Xr mandoc_char 7
-for a complete list.
-Examples include
-.Sq \e*(Am
-.Pq ampersand
-and
-.Sq \e*(Ba
-.Pq vertical bar .
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \e*(Am
+ampersand
+.It \e*(Ba
+vertical bar
+.El
+.Pp
+These strings are set using
+.Xr roff 7 ,
+although
+.Nm
+consists of several pre-set escapes listed in
+.Xr mandoc_char 7 .
.Ss Whitespace
Whitespace consists of the space character.
-In free-form lines, whitespace is preserved within a line; un-escaped
-trailing spaces are stripped from input (unless in a literal context).
-Blank free-form lines, which may include whitespace, are only permitted
-within literal contexts.
-.Pp
+In text lines, whitespace is preserved within a line.
In macro lines, whitespace delimits arguments and is discarded.
-If arguments are quoted, whitespace within the quotes is retained.
-.Ss Quotation
-Macro arguments may be quoted with a double-quote to group
-space-delimited terms or to retain blocks of whitespace.
-A quoted argument begins with a double-quote preceded by whitespace.
-The next double-quote not pair-wise adjacent to another double-quote
-terminates the literal, regardless of surrounding whitespace.
.Pp
-This produces tokens
-.Sq a" ,
-.Sq b c ,
-.Sq de ,
-and
-.Sq fg" .
-Note that any quoted term, be it argument or macro, is indiscriminately
-considered literal text.
-Thus, the following produces
-.Sq \&Em a :
-.Bd -literal -offset indent
-\&.Em "Em a"
-.Ed
+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
-In free-form mode, quotes are regarded as opaque text.
-.Ss Dates
-There are several macros in
-.Nm
-that require a date argument.
-The canonical form for dates is the American format:
+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 Quotation
+Macro arguments may be quoted with double-quotes; in this case,
+whitespace within the quotes is retained as part of the argument.
+For example,
.Pp
-.D1 Cm Month Day , Year
+.D1 Pf \. \&Fn strlen "\(dqconst char *s\(dq"
.Pp
-The
-.Cm Day
-value is an optionally zero-padded numeral.
-The
-.Cm Month
-value is the full month name.
-The
-.Cm Year
-value is the full four-digit year.
+renders as
+.Sq Fn strlen "const char *s" ,
+while
.Pp
-Reduced form dates are broken-down canonical form dates:
+.D1 Pf \. \&Fn strlen "const char *s"
.Pp
-.D1 Cm Month , Year
-.D1 Cm Year
+would produce
+.Sq Fn strlen const char *s .
.Pp
-Some examples of valid dates follow:
+A quoted argument begins with a double-quote preceded by whitespace.
+The next double-quote not pairwise adjacent to another double-quote
+terminates the literal, regardless of surrounding whitespace.
.Pp
-.D1 "May, 2009" Pq reduced form
-.D1 "2009" Pq reduced form
-.D1 "May 20, 2009" Pq canonical form
-.Ss Scaling Widths
-Many macros support scaled widths for their arguments, such as
-stipulating a two-inch list indentation with the following:
+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
+Note that any quoted text, even if it would cause a macro invocation
+when unquoted, is considered literal text.
+Thus, the following produces
+.Sq Op "Fl a" :
.Bd -literal -offset indent
-\&.Bl -tag -width 2i
+\&.Op "Fl a"
.Ed
.Pp
-The syntax for scaled widths is
+In text lines, quotes are regarded as opaque text.
+.Ss Scaling Widths
+Many 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 proceeded 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
is necessarily non-portable across output media.
See
.Sx COMPATIBILITY .
+.Pp
+Examples:
+.Bl -tag -width Ds -offset indent -compact
+.It \&.Bl -tag -width 2i
+two-inch tagged list indentation
+.Pq see Sx \&Bl
+.It \&.sp 2v
+two vertical spaces
+.Pq see Sx \&sp
+.El
.Ss Sentence Spacing
-When composing a manual, make sure that your sentences end at the end of
-a line.
-By doing so, front-ends will be able to apply the proper amount of
+Sentences 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.
+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 MANUAL STRUCTURE
A well-formed
.Nm
document consists of a document prologue followed by one or more
sections.
.Pp
-The prologue, which consists of (in order) the
+The prologue, which consists of the
.Sx \&Dd ,
.Sx \&Dt ,
and
.Sx \&Os
-macros, is required for every document.
+macros in that order, is required for every document.
.Pp
The first section (sections are denoted by
.Sx \&Sh )
followed by
.Sx \&Nd .
.Pp
-Following that, convention dictates specifying at least the SYNOPSIS and
-DESCRIPTION sections, although this varies between manual sections.
+Following that, convention dictates specifying at least the
+.Em SYNOPSIS
+and
+.Em DESCRIPTION
+sections, although this varies between manual sections.
.Pp
The following is a well-formed skeleton
.Nm
-file:
+file for a utility
+.Qq progname :
.Bd -literal -offset indent
\&.Dd $\&Mdocdate$
-\&.Dt mdoc 7
+\&.Dt PROGNAME section
\&.Os
-\&.
\&.Sh NAME
-\&.Nm foo
-\&.Nd a description goes here
-\&.\e\*q The next is for sections 2 & 3 only.
+\&.Nm progname
+\&.Nd one line about what it does
\&.\e\*q .Sh LIBRARY
-\&.
+\&.\e\*q For sections 2, 3, & 9 only.
+\&.\e\*q Not used in OpenBSD.
\&.Sh SYNOPSIS
-\&.Nm foo
+\&.Nm progname
\&.Op Fl options
\&.Ar
-\&.
\&.Sh DESCRIPTION
The
\&.Nm
utility processes files ...
\&.\e\*q .Sh IMPLEMENTATION NOTES
-\&.\e\*q The next is for sections 2, 3, & 9 only.
+\&.\e\*q Not used in OpenBSD.
\&.\e\*q .Sh RETURN VALUES
-\&.\e\*q The next is for sections 1, 6, 7, & 8 only.
+\&.\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 The next is for sections 1 & 8 only.
\&.\e\*q .Sh EXIT STATUS
+\&.\e\*q For sections 1, 6, & 8 only.
\&.\e\*q .Sh EXAMPLES
-\&.\e\*q The next is for sections 1, 4, 6, 7, & 8 only.
\&.\e\*q .Sh DIAGNOSTICS
-\&.\e\*q The next is for sections 2, 3, & 9 only.
+\&.\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 .Xr foobar 1
\&.\e\*q .Sh STANDARDS
\&.\e\*q .Sh CAVEATS
\&.\e\*q .Sh BUGS
\&.\e\*q .Sh SECURITY CONSIDERATIONS
+\&.\e\*q Not used in OpenBSD.
.Ed
.Pp
-The sections in a
+The sections in an
.Nm
document are conventionally ordered as they appear above.
Sections should be composed as follows:
.Bl -ohang -offset Ds
.It Em NAME
-The name(s) and a short description of the documented material.
+The name(s) and a one line description of the documented material.
The syntax for this as follows:
.Bd -literal -offset indent
-\&.Nm name0
-\&.Nm name1
+\&.Nm name0 ,
+\&.Nm name1 ,
\&.Nm name2
-\&.Nd a short description
+\&.Nd a one line description
.Ed
.Pp
+Multiple
+.Sq \&Nm
+names should be separated by commas.
+.Pp
The
.Sx \&Nm
macro(s) must precede the
.Sx \&Nd .
.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.
+assumed to be a function in a section 2, 3, or 9 manual.
The syntax for this is as follows:
.Bd -literal -offset indent
\&.Lb libarm
For the first, utilities (sections 1, 6, and 8), this is
generally structured as follows:
.Bd -literal -offset indent
-\&.Nm foo
+\&.Nm bar
\&.Op Fl v
\&.Op Fl o Ar file
\&.Op Ar
-\&.Nm bar
+\&.Nm foo
\&.Op Fl v
\&.Op Fl o Ar file
\&.Op Ar
.Ed
.Pp
+Commands should be ordered alphabetically.
+.Pp
For the second, function calls (sections 2, 3, 9):
.Bd -literal -offset indent
-\&.Vt extern const char *global;
\&.In header.h
+\&.Vt extern const char *global;
\&.Ft "char *"
\&.Fn foo "const char *src"
\&.Ft "char *"
\&.Fn bar "const char *src"
.Ed
.Pp
+Ordering of
+.Sx \&In ,
+.Sx \&Vt ,
+.Sx \&Fn ,
+and
+.Sx \&Fo
+macros should follow C header-file conventions.
+.Pp
And for the third, configurations (section 4):
.Bd -literal -offset indent
\&.Cd \*qit* at isa? port 0x2e\*q
Manuals not in these sections generally don't need a
.Em SYNOPSIS .
.Pp
-See
-.Sx \&Op ,
+Some macros are displayed differently in the
+.Em SYNOPSIS
+section, particularly
+.Sx \&Nm ,
.Sx \&Cd ,
+.Sx \&Fd ,
+.Sx \&Fn ,
+.Sx \&Fo ,
+.Sx \&In ,
+.Sx \&Vt ,
+and
+.Sx \&Ft .
+All of these macros are output on their own line.
+If two such dissimilar macros are pairwise invoked (except for
+.Sx \&Ft
+before
+.Sx \&Fo
+or
+.Sx \&Fn ) ,
+they are separated by a vertical space, unless in the case of
+.Sx \&Fo ,
.Sx \&Fn ,
-.Sx \&Ft ,
and
-.Sx \&Vt .
+.Sx \&Ft ,
+which are always separated by vertical space.
+.Pp
+When text and macros following an
+.Sx \&Nm
+macro starting an input line span multiple output lines,
+all output lines but the first will be indented to align
+with the text immediately following the
+.Sx \&Nm
+macro, up to the next
+.Sx \&Nm ,
+.Sx \&Sh ,
+or
+.Sx \&Ss
+macro or the end of an enclosing block, whichever comes first.
.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
+This begins with an expansion of the brief, one line description in
+.Em NAME :
+.Bd -literal -offset indent
+The
+\&.Nm
+utility does this, that, and the other.
+.Ed
+.Pp
+It usually follows with a breakdown of the options (if documenting a
command), such as:
.Bd -literal -offset indent
The arguments are as follows:
.Ed
.Pp
Manuals not documenting a command won't include the above fragment.
+.Pp
+Since the
+.Em DESCRIPTION
+section usually contains most of the text of a manual, longer manuals
+often use the
+.Sx \&Ss
+macro to form subsections.
+In very long manuals, the
+.Em DESCRIPTION
+may be split into multiple sections, each started by an
+.Sx \&Sh
+macro followed by a non-standard section name, and each having
+several subsections, like in the present
+.Nm
+manual.
.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 is the dual of
-.Em EXIT STATUS ,
-which is used for commands.
-It documents the return values of functions in sections 2, 3, and 9.
+This section documents the
+return values of functions in sections 2, 3, and 9.
.Pp
See
.Sx \&Rv .
.It Em ENVIRONMENT
-Documents any usages of environment variables, e.g.,
-.Xr environ 7 .
+Lists the environment variables used by the utility,
+and explains the syntax and semantics of their values.
+The
+.Xr environ 7
+manual provides examples of typical content and formatting.
.Pp
See
.Sx \&Ev .
.It Em FILES
Documents files used.
-It's helpful to document both the file and a short description of how
+It's helpful to document both the file name and a short description of how
the file is used (created, modified, etc.).
.Pp
See
.Sx \&Pa .
.It Em EXIT STATUS
-Command exit status for section 1, 6, and 8 manuals.
-This section is the dual of
-.Em RETURN VALUES ,
-which is used for functions.
+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 doubly sure that your examples work properly!
+Make sure that examples work properly!
.It Em DIAGNOSTICS
Documents error conditions.
This is most useful in section 4 manuals.
Cross-references should conventionally be ordered first by section, then
alphabetically.
.Pp
+References to other documentation concerning the topic of the manual page,
+for example authoritative books or journal articles, may also be
+provided in this section.
+.Pp
See
+.Sx \&Rs
+and
.Sx \&Xr .
.It Em STANDARDS
References any standards implemented or used.
See
.Sx \&St .
.It Em HISTORY
-The history of any manual without a
-.Em STANDARDS
-section should be described in this section.
+A brief history of the subject, including where it was first implemented,
+and when it was ported to or reimplemented for the operating system at hand.
.It Em AUTHORS
-Credits to authors, if applicable, should appear in this section.
-Authors should generally be noted by both name and an e-mail address.
+Credits to the person or persons who wrote the code and/or documentation.
+Authors should generally be noted by both name and email address.
.Pp
See
.Sx \&An .
.It Em CAVEATS
-Explanations of common misuses and misunderstandings should be explained
+Common misuses and misunderstandings should be explained
in this section.
.It Em BUGS
-Extant bugs should be described in this section.
+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 three characters in length and begin with a
-control character ,
+control character,
.Sq \&. ,
at the beginning of the line.
An arbitrary amount of whitespace may sit between the control character
.Pp
The
.Em Callable
-column indicates that the macro may be called subsequent to the initial
-line-macro.
-If a macro is not callable, then its invocation after the initial line
-macro is interpreted as opaque text, such that
+column indicates that the macro may also be called by passing its name
+as an argument to another macro.
+For example,
+.Sq \&.Op \&Fl O \&Ar file
+produces
+.Sq Op Fl O Ar file .
+To prevent a macro call and render the macro name literally,
+escape it by prepending a zero-width space,
+.Sq \e& .
+For example,
+.Sq \&Op \e&Fl O
+produces
+.Sq Op \&Fl O .
+If a macro is not callable but its name appears as an argument
+to another macro, it is interpreted as opaque text.
+For example,
.Sq \&.Fl \&Sh
produces
.Sq Fl \&Sh .
.Pp
The
-.Em Parsable
-column indicates whether the macro may be followed by further
-(ostensibly callable) macros.
-If a macro is not parsable, subsequent macro invocations on the line
-will be interpreted as opaque text.
+.Em Parsed
+column indicates whether the macro may call other macros by receiving
+their names as arguments.
+If a macro is not parsed but the name of another macro appears
+as an argument, it is interpreted as opaque text.
.Pp
The
.Em Scope
Multi-line scope closed by an explicit closing macro.
All macros contains bodies; only
.Sx \&Bf
-contains a head.
+and
+.Pq optionally
+.Sx \&Bl
+contain a head.
.Bd -literal -offset indent
\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
\(lBbody...\(rB
\&.Yc
.Ed
.Pp
-.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXX"
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsedX" "closed by XXX"
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
.It Sx \&Bd Ta \&No Ta \&No Ta closed by Sx \&Ed
.It Sx \&Bf Ta \&No Ta \&No Ta closed by Sx \&Ef
.It Sx \&Bk Ta \&No Ta \&No Ta closed by Sx \&Ek
.Pc
don't have heads; only one
.Po
-.Sx \&It Fl column
+.Sx \&It
+in
+.Sx \&Bl Fl column
.Pc
has multiple heads.
.Bd -literal -offset indent
\(lBbody...\(rB
.Ed
.Pp
-.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXXXXXXXXXX"
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
-.It Sx \&It Ta \&No Ta Yes Ta closed by Sx \&It , Sx \&El
-.It Sx \&Nd Ta \&No Ta \&No Ta closed by Sx \&Sh
-.It Sx \&Sh Ta \&No Ta \&No Ta closed by Sx \&Sh
-.It Sx \&Ss Ta \&No Ta \&No Ta closed by Sx \&Sh , Sx \&Ss
+.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsedX" "closed by XXXXXXXXXXX"
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
+.It Sx \&It Ta \&No Ta Yes Ta closed by Sx \&It , Sx \&El
+.It Sx \&Nd Ta \&No Ta \&No Ta closed by Sx \&Sh
+.It Sx \&Nm Ta \&No Ta Yes Ta closed by Sx \&Nm , Sx \&Sh , Sx \&Ss
+.It Sx \&Sh Ta \&No Ta Yes Ta closed by Sx \&Sh
+.It Sx \&Ss Ta \&No Ta Yes Ta closed by Sx \&Sh , Sx \&Ss
.El
+.Pp
+Note that the
+.Sx \&Nm
+macro is a
+.Sx Block full-implicit
+macro only when invoked as the first macro
+in a
+.Em SYNOPSIS
+section line, else it is
+.Sx In-line .
.Ss Block partial-explicit
Like block full-explicit, but also with single-line scope.
Each has at least a body and, in limited circumstances, a head
\(lBbody...\(rB \&Yc \(lBtail...\(rB
.Ed
.Pp
-.Bl -column "MacroX" "CallableX" "ParsableX" "closed by XXXX" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
.It Sx \&Ac Ta Yes Ta Yes Ta opened by Sx \&Ao
.It Sx \&Ao Ta Yes Ta Yes Ta closed by Sx \&Ac
.It Sx \&Bc Ta Yes Ta Yes Ta closed by Sx \&Bo
.It Sx \&Xo Ta Yes Ta Yes Ta closed by Sx \&Xc
.El
.Ss Block partial-implicit
-Like block full-implicit, but with single-line scope closed by
-.Sx Reserved Characters
-or end of line.
+Like block full-implicit, but with single-line scope closed by the
+end of the line.
.Bd -literal -offset indent
\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
.Ed
.Pp
-.Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable
+.Bl -column "MacroX" "CallableX" "ParsedX" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed
.It Sx \&Aq Ta Yes Ta Yes
.It Sx \&Bq Ta Yes Ta Yes
.It Sx \&Brq Ta Yes Ta Yes
macro is a
.Sx Block partial-implicit
only when invoked as the first macro
-in a SYNOPSIS section line, else it is
+in a
+.Em SYNOPSIS
+section line, else it is
.Sx In-line .
+.Ss Special block macro
+The
+.Sx \&Ta
+macro can only be used below
+.Sx \&It
+in
+.Sx \&Bl Fl column
+lists.
+It delimits blocks representing table cells;
+these blocks have bodies, but no heads.
+.Pp
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
+.It Sx \&Ta Ta Yes Ta Yes Ta closed by Sx \&Ta , Sx \&It
+.El
.Ss In-line
-Closed by
-.Sx Reserved Characters ,
-end of line, fixed argument lengths, and/or subsequent macros.
+Closed by the end of the line, fixed argument lengths,
+and/or subsequent macros.
In-line macros have only text children.
If a number (or inequality) of arguments is
.Pq n ,
then the macro accepts an arbitrary number of arguments.
.Bd -literal -offset indent
-\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lbres...\(rb
+\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lBres...\(rB
\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...
\&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
.Ed
.Pp
-.Bl -column "MacroX" "CallableX" "ParsableX" "Arguments" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Arguments
+.Bl -column "MacroX" "CallableX" "ParsedX" "Arguments" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Arguments
.It Sx \&%A Ta \&No Ta \&No Ta >0
.It Sx \&%B Ta \&No Ta \&No Ta >0
.It Sx \&%C Ta \&No Ta \&No Ta >0
.It Sx \&%T Ta \&No Ta \&No Ta >0
.It Sx \&%U Ta \&No Ta \&No Ta >0
.It Sx \&%V Ta \&No Ta \&No Ta >0
-.It Sx \&Ad Ta Yes Ta Yes Ta n
-.It Sx \&An Ta Yes Ta Yes Ta n
+.It Sx \&Ad Ta Yes Ta Yes Ta >0
+.It Sx \&An Ta Yes Ta Yes Ta >0
.It Sx \&Ap Ta Yes Ta Yes Ta 0
.It Sx \&Ar Ta Yes Ta Yes Ta n
.It Sx \&At Ta Yes Ta Yes Ta 1
.It Sx \&Bt Ta \&No Ta \&No Ta 0
.It Sx \&Bx Ta Yes Ta Yes Ta n
.It Sx \&Cd Ta Yes Ta Yes Ta >0
-.It Sx \&Cm Ta Yes Ta Yes Ta n
+.It Sx \&Cm Ta Yes Ta Yes Ta >0
.It Sx \&Db Ta \&No Ta \&No Ta 1
-.It Sx \&Dd Ta \&No Ta \&No Ta >0
+.It Sx \&Dd Ta \&No Ta \&No Ta n
.It Sx \&Dt Ta \&No Ta \&No Ta n
-.It Sx \&Dv Ta Yes Ta Yes Ta n
+.It Sx \&Dv Ta Yes Ta Yes Ta >0
.It Sx \&Dx Ta Yes Ta Yes Ta n
.It Sx \&Em Ta Yes Ta Yes Ta >0
.It Sx \&En Ta \&No Ta \&No Ta 0
.It Sx \&Er Ta Yes Ta Yes Ta >0
.It Sx \&Es Ta \&No Ta \&No Ta 0
-.It Sx \&Ev Ta Yes Ta Yes Ta n
+.It Sx \&Ev Ta Yes Ta Yes Ta >0
.It Sx \&Ex Ta \&No Ta \&No Ta n
-.It Sx \&Fa Ta Yes Ta Yes Ta n
+.It Sx \&Fa Ta Yes Ta Yes Ta >0
.It Sx \&Fd Ta \&No Ta \&No Ta >0
.It Sx \&Fl Ta Yes Ta Yes Ta n
.It Sx \&Fn Ta Yes Ta Yes Ta >0
.It Sx \&Fr Ta \&No Ta \&No Ta n
-.It Sx \&Ft Ta Yes Ta Yes Ta n
+.It Sx \&Ft Ta Yes Ta Yes Ta >0
.It Sx \&Fx Ta Yes Ta Yes Ta n
.It Sx \&Hf Ta \&No Ta \&No Ta n
.It Sx \&Ic Ta Yes Ta Yes Ta >0
-.It Sx \&In Ta \&No Ta \&No Ta n
+.It Sx \&In Ta \&No Ta \&No Ta 1
.It Sx \&Lb Ta \&No Ta \&No Ta 1
-.It Sx \&Li Ta Yes Ta Yes Ta n
-.It Sx \&Lk Ta Yes Ta Yes Ta n
+.It Sx \&Li Ta Yes Ta Yes Ta >0
+.It Sx \&Lk Ta Yes Ta Yes Ta >0
.It Sx \&Lp Ta \&No Ta \&No Ta 0
.It Sx \&Ms Ta Yes Ta Yes Ta >0
.It Sx \&Mt Ta Yes Ta Yes Ta >0
.It Sx \&br Ta \&No Ta \&No Ta 0
.It Sx \&sp Ta \&No Ta \&No Ta 1
.El
+.Ss Delimiters
+When a macro argument consists of one single input character
+considered as a delimiter, the argument gets special handling.
+This does not apply when delimiters appear in arguments containing
+more than one character.
+Consequently, to prevent special handling and just handle it
+like any other argument, a delimiter can be escaped by prepending
+a zero-width space
+.Pq Sq \e& .
+In text lines, delimiters never need escaping, but may be used
+as normal punctuation.
+.Pp
+For many macros, when the leading arguments are opening delimiters,
+these delimiters are put before the macro scope,
+and when the trailing arguments are closing delimiters,
+these delimiters are put after the macro scope.
+For example,
+.Pp
+.D1 Pf \. \&Aq "( [ word ] ) ."
+.Pp
+renders as:
+.Pp
+.D1 Aq ( [ word ] ) .
+.Pp
+Opening delimiters are:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It \&(
+left parenthesis
+.It \&[
+left bracket
+.El
+.Pp
+Closing delimiters are:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It \&.
+period
+.It \&,
+comma
+.It \&:
+colon
+.It \&;
+semicolon
+.It \&)
+right parenthesis
+.It \&]
+right bracket
+.It \&?
+question mark
+.It \&!
+exclamation mark
+.El
+.Pp
+Note that even a period preceded by a backslash
+.Pq Sq \e.\&
+gets this special handling; use
+.Sq \e&.
+to prevent that.
+.Pp
+Many in-line macros interrupt their scope when they encounter
+delimiters, and resume their scope when more arguments follow that
+are not delimiters.
+For example,
+.Pp
+.D1 Pf \. \&Fl "a ( b | c \e*(Ba d ) e"
+.Pp
+renders as:
+.Pp
+.D1 Fl a ( b | c \*(Ba d ) e
+.Pp
+This applies to both opening and closing delimiters,
+and also to the middle delimiter:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It \&|
+vertical bar
+.El
+.Pp
+As a special case, the predefined string \e*(Ba is handled and rendered
+in the same way as a plain
+.Sq \&|
+character.
+Using this predefined string is not recommended in new manuals.
.Sh REFERENCE
This section is a canonical reference of all macros, arranged
alphabetically.
.Ss \&%A
Author name of an
.Sx \&Rs
-block. Multiple authors should each be accorded their own
+block.
+Multiple authors should each be accorded their own
.Sx \%%A
-line. Author names should be ordered with full or abbreviated
-forename(s) first, then full surname.
+line.
+Author names should be ordered with full or abbreviated forename(s)
+first, then full surname.
.Ss \&%B
Book title of an
.Sx \&Rs
-block. This macro may also be used in a non-bibliographic context when
+block.
+This macro may also be used in a non-bibliographic context when
referring to book titles.
.Ss \&%C
Publication city or location of an
.Sx \&Rs
block.
-.Pp
-.Em Remarks :
-this macro is not implemented in
-.Xr groff 1 .
.Ss \&%D
Publication date of an
.Sx \&Rs
-block. This should follow the reduced or canonical form syntax
-described in
-.Sx Dates .
+block.
+Recommended formats of arguments are
+.Ar month day , year
+or just
+.Ar year .
.Ss \&%I
Publisher or issuer name of an
.Sx \&Rs
.Ss \&%Q
Institutional author (school, government, etc.) of an
.Sx \&Rs
-block. Multiple institutional authors should each be accorded their own
+block.
+Multiple institutional authors should each be accorded their own
.Sx \&%Q
line.
.Ss \&%R
.Ss \&%T
Article title of an
.Sx \&Rs
-block. This macro may also be used in a non-bibliographical context
-when referring to article titles.
+block.
+This macro may also be used in a non-bibliographical context when
+referring to article titles.
.Ss \&%U
URI of reference document.
.Ss \&%V
.Sx \&Rs
block.
.Ss \&Ac
-Closes an
+Close an
.Sx \&Ao
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Ad
-Address construct: usually in the context of an computational address in
-memory, not a physical (post) address.
+Memory address.
+Do not use this for postal addresses.
.Pp
Examples:
-.D1 \&.Ad [0,$]
-.D1 \&.Ad 0x00000000
+.Dl \&.Ad [0,$]
+.Dl \&.Ad 0x00000000
.Ss \&An
Author name.
-This macro may alternatively accepts the following arguments, although
-these may not be specified along with a parameter:
-.Bl -tag -width 12n -offset indent
+Can be used both for the authors of the program, function, or driver
+documented in the manual, or for the authors of the manual itself.
+Requires either the name of an author or one of the following arguments:
+.Pp
+.Bl -tag -width "-nosplitX" -offset indent -compact
.It Fl split
-Renders a line break before each author listing.
+Start a new output line before each subsequent invocation of
+.Sx \&An .
.It Fl nosplit
The opposite of
.Fl split .
.El
.Pp
-In the AUTHORS section, the default is not to split the first author
-listing, but all subsequent author listings, whether or not they're
-interspersed by other macros or text, are split.
-Thus, specifying
+The default is
+.Fl nosplit .
+The effect of selecting either of the
+.Fl split
+modes ends at the beginning of the
+.Em AUTHORS
+section.
+In the
+.Em AUTHORS
+section, the default is
+.Fl nosplit
+for the first author listing and
.Fl split
-will cause the first listing also to be split.
-If not in the AUTHORS section, the default is not to split.
+for all other author listings.
.Pp
Examples:
-.D1 \&.An -nosplit
-.D1 \&.An J. D. Ullman .
-.Pp
-.Em Remarks :
-the effects of
-.Fl split
-or
-.Fl nosplit
-are re-set when entering the AUTHORS section, so if one specifies
-.Sx \&An Fl nosplit
-in the general document body, it must be re-specified in the AUTHORS
-section.
+.Dl \&.An -nosplit
+.Dl \&.An Kristaps Dzonsons \&Aq kristaps@bsd.lv
.Ss \&Ao
-Begins a block enclosed by angled brackets.
+Begin a block enclosed by angle brackets.
Does not have any head arguments.
.Pp
Examples:
-.D1 \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac
+.Dl \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac
.Pp
See also
.Sx \&Aq .
.Ss \&Ap
-Inserts an apostrophe without any surrounding white-space.
-This is generally used as a grammatic device when referring to the verb
-form of a function:
-.Bd -literal -offset indent
-\&.Fn execve Ap d
-.Ed
+Inserts an apostrophe without any surrounding whitespace.
+This is generally used as a grammatical device when referring to the verb
+form of a function.
+.Pp
+Examples:
+.Dl \&.Fn execve \&Ap d
.Ss \&Aq
-Encloses its arguments in angled brackets.
+Encloses its arguments in angle brackets.
.Pp
Examples:
-.D1 \&.Fl -key= \&Ns \&Aq \&Ar val
+.Dl \&.Fl -key= \&Ns \&Aq \&Ar val
.Pp
.Em Remarks :
this macro is often abused for rendering URIs, which should instead use
.Ss \&Ar
Command arguments.
If an argument is not provided, the string
-.Dq file ...
+.Dq file ...\&
is used as a default.
.Pp
Examples:
-.D1 \&.Fl o \&Ns \&Ar file1
-.D1 \&.Ar
-.D1 \&.Ar arg1 , arg2 .
+.Dl ".Fl o Ar file"
+.Dl ".Ar"
+.Dl ".Ar arg1 , arg2 ."
+.Pp
+The arguments to the
+.Sx \&Ar
+macro are names and placeholders for command arguments;
+for fixed strings to be passed verbatim as arguments, use
+.Sx \&Fl
+or
+.Sx \&Cm .
.Ss \&At
Formats an AT&T version.
-Accepts at most one parameter:
-.Bl -tag -width 12n -offset indent
+Accepts one optional argument:
+.Pp
+.Bl -tag -width "v[1-7] | 32vX" -offset indent -compact
.It Cm v[1-7] | 32v
A version of
.At .
+.It Cm III
+.At III .
.It Cm V[.[1-4]]?
-A system version of
-.At .
+A version of
+.At V .
.El
.Pp
-Note that these parameters do not begin with a hyphen.
+Note that these arguments do not begin with a hyphen.
.Pp
Examples:
-.D1 \&.At
-.D1 \&.At V.1
+.Dl \&.At
+.Dl \&.At III
+.Dl \&.At V.1
.Pp
See also
.Sx \&Bsx ,
and
.Sx \&Ux .
.Ss \&Bc
-Closes a
+Close a
.Sx \&Bo
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Bd
-Begins a display block.
-A display is collection of macros or text which may be collectively
-offset or justified in a manner different from that
-of the enclosing context.
-By default, the block is preceded by a vertical space.
-.Pp
-Each display is associated with a type, which must be one of the
-following arguments:
-.Bl -tag -width 12n -offset indent
-.It Fl ragged
-Only left-justify the block.
-.It Fl unfilled
-Do not justify the block at all.
+Begin a display block.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bd
+.Fl Ns Ar type
+.Op Fl offset Ar width
+.Op Fl compact
+.Ed
+.Pp
+Display blocks are used to select a different indentation and
+justification than the one used by the surrounding text.
+They may contain both macro lines and text lines.
+By default, a display block is preceded by a vertical space.
+.Pp
+The
+.Ar type
+must be one of the following:
+.Bl -tag -width 13n -offset indent
+.It Fl centered
+Produce one output line from each input line, and centre-justify each line.
+Using this display type is not recommended; many
+.Nm
+implementations render it poorly.
.It Fl filled
-Left- and right-justify the block.
+Change the positions of line breaks to fill each line, and left- and
+right-justify the resulting block.
.It Fl literal
-Alias for
-.Fl unfilled .
-.It Fl centered
-Centre-justify each line.
+Produce one output line from each input line,
+and do not justify the block at all.
+Preserve white space as it appears in the input.
+Always use a constant-width font.
+Use this for displaying source code.
+.It Fl ragged
+Change the positions of line breaks to fill each line, and left-justify
+the resulting block.
+.It Fl unfilled
+The same as
+.Fl literal ,
+but using the same font as for normal text, which is a variable width font
+if supported by the output device.
.El
.Pp
-The type must be provided first.
-Secondary arguments are as follows:
-.Bl -tag -width 12n -offset indent
+The
+.Ar type
+must be provided first.
+Additional arguments may follow:
+.Bl -tag -width 13n -offset indent
.It Fl offset Ar width
-Offset by the value of
+Indent the display by the
.Ar width ,
-which is interpreted as one of the following, specified in order:
+which may be one of the following:
.Bl -item
.It
-As one of the pre-defined strings
-.Ar indent ,
-the width of standard indentation;
-.Ar indent-two ,
+One of the pre-defined strings
+.Cm indent ,
+the width of a standard indentation (six constant width characters);
+.Cm indent-two ,
twice
-.Ar indent ;
-.Ar left ,
-which has no effect ;
-.Ar right ,
-which justifies to the right margin; and
-.Ar center ,
+.Cm indent ;
+.Cm left ,
+which has no effect;
+.Cm right ,
+which justifies to the right margin; or
+.Cm center ,
which aligns around an imagined centre axis.
.It
-As a precalculated width for a named macro.
+A macro invocation, which selects a predefined width
+associated with that macro.
The most popular is the imaginary macro
.Ar \&Ds ,
which resolves to
-.Ar 6n .
+.Sy 6n .
.It
-As a scaling unit following the syntax described in
+A width using the syntax described in
.Sx Scaling Widths .
.It
-As the calculated string length of the opaque string.
+An arbitrary string, which indents by the length of this string.
.El
.Pp
-If unset, it will revert to the value of
-.Ar 8n
-as described in
-.Sx Scaling Widths .
+When the argument is missing,
+.Fl offset
+is ignored.
.It Fl compact
-Do not assert a vertical space before the block.
-.It Fl file Ar file
-Prepend the file
-.Ar file
-before any text or macros within the block.
+Do not assert vertical space before the display.
.El
.Pp
Examples:
.Bd -literal -offset indent
-\&.Bd \-unfilled \-offset two-indent \-compact
+\&.Bd \-literal \-offset indent \-compact
Hello world.
\&.Ed
.Ed
and
.Sx \&Dl .
.Ss \&Bf
-.Ss \&Bk
-.Ss \&Bl
-Begins a list composed of one or more list entries.
-A list is associated with a type, which is a required argument.
-Other arguments are
-.Fl width ,
-defined per-type as accepting a literal or
-.Sx Scaling Widths
-value;
-.Fl offset ,
-also accepting a literal or
-.Sx Scaling Widths
-value setting the list's global offset; and
-.Fl compact ,
-suppressing the default vertical space printed before each list entry.
-A list entry is specified by the
-.Sx \&It
-macro, which consists of a head and optional body (depending on the list
-type).
-A list must specify one of the following list types:
-.Bl -tag -width 12n -offset indent
-.It Fl bullet
-A list offset by a bullet.
-The head of list entries must be empty.
-List entry bodies are positioned after the bullet.
-The
-.Fl width
-argument varies the width of list bodies' left-margins.
-.It Fl column
-A columnated list.
+Change the font mode for a scoped block of text.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bf
+.Oo
+.Fl emphasis | literal | symbolic |
+.Cm \&Em | \&Li | \&Sy
+.Oc
+.Ed
+.Pp
The
-.Fl width
-argument has no effect.
-The number of columns is specified as parameters to the
-.Sx \&Bl
-macro.
-These dictate the width of columns either as
-.Sx Scaling Widths
-or literal text.
-List entry bodies must be left empty.
-Column bodies have the following syntax:
+.Fl emphasis
+and
+.Cm \&Em
+argument are equivalent, as are
+.Fl symbolic
+and
+.Cm \&Sy ,
+and
+.Fl literal
+and
+.Cm \&Li .
+Without an argument, this macro does nothing.
+The font mode continues until broken by a new font mode in a nested
+scope or
+.Sx \&Ef
+is encountered.
.Pp
-.D1 .It col1 <TAB> ... coln
-.D1 .It col1 Ta ... coln
-.D1 .It col1 <TAB> col2 Ta coln
+See also
+.Sx \&Li ,
+.Sx \&Ef ,
+.Sx \&Em ,
+and
+.Sx \&Sy .
+.Ss \&Bk
+For each macro, keep its output together on the same output line,
+until the end of the macro or the end of the input line is reached,
+whichever comes first.
+Line breaks in text lines are unaffected.
+The syntax is as follows:
.Pp
-where columns may be separated by tabs, the literal string
-.Qq Ta ,
-or a mixture of both.
-These are equivalent except that quoted sections propogate over tabs,
-for example,
+.D1 Pf \. Sx \&Bk Fl words
.Pp
-.D1 .It \(dqcol1 ; <TAB> col2 ;\(dq ;
+The
+.Fl words
+argument is required; additional arguments are ignored.
.Pp
-will preserve the semicolon whitespace except for the last.
-.It Fl dash
-A list offset by a dash (hyphen).
-The head of list entries must be empty.
-List entry bodies are positioned past the dash.
+The following example will not break within each
+.Sx \&Op
+macro line:
+.Bd -literal -offset indent
+\&.Bk \-words
+\&.Op Fl f Ar flags
+\&.Op Fl o Ar output
+\&.Ek
+.Ed
+.Pp
+Be careful in using over-long lines within a keep block!
+Doing so will clobber the right margin.
+.Ss \&Bl
+Begin a list.
+Lists consist of items specified using the
+.Sx \&It
+macro, containing a head or a body or both.
+The list syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bl
+.Fl Ns Ar type
+.Op Fl width Ar val
+.Op Fl offset Ar val
+.Op Fl compact
+.Op HEAD ...
+.Ed
+.Pp
+The list
+.Ar type
+is mandatory and must be specified first.
The
.Fl width
-argument varies the width of list bodies' left-margins.
-.It Fl diag
-Like
-.Fl inset ,
-but with additional formatting to the head.
+and
+.Fl offset
+arguments accept
+.Sx Scaling Widths
+or use the length of the given string.
The
+.Fl offset
+is a global indentation for the whole list, affecting both item heads
+and bodies.
+For those list types supporting it, the
.Fl width
-argument varies the width of list bodies' left-margins.
-.It Fl enum
-An enumerated list offset by the enumeration from 1.
-The head of list entries must be empty.
-List entry bodies are positioned after the enumeration.
+argument requests an additional indentation of item bodies,
+to be added to the
+.Fl offset .
+Unless the
+.Fl compact
+argument is specified, list entries are separated by vertical space.
+.Pp
+A list must specify one of the following list types:
+.Bl -tag -width 12n -offset indent
+.It Fl bullet
+No item heads can be specified, but a bullet will be printed at the head
+of each item.
+Item bodies start on the same output line as the bullet
+and are indented according to the
+.Fl width
+argument.
+.It Fl column
+A columnated list.
The
.Fl width
-argument varies the width of list bodies' left-margins.
+argument has no effect; instead, each argument specifies the width
+of one column, using either the
+.Sx Scaling Widths
+syntax or the string length of the argument.
+If the first line of the body of a
+.Fl column
+list is not an
+.Sx \&It
+macro line,
+.Sx \&It
+contexts spanning one input line each are implied until an
+.Sx \&It
+macro line is encountered, at which point items start being interpreted as
+described in the
+.Sx \&It
+documentation.
+.It Fl dash
+Like
+.Fl bullet ,
+except that dashes are used in place of bullets.
+.It Fl diag
+Like
+.Fl inset ,
+except that item heads are not parsed for macro invocations.
+Most often used in the
+.Em DIAGNOSTICS
+section with error constants in the item heads.
+.It Fl enum
+A numbered list.
+No item heads can be specified.
+Formatted like
+.Fl bullet ,
+except that cardinal numbers are used in place of bullets,
+starting at 1.
.It Fl hang
Like
.Fl tag ,
-but instead of list bodies positioned after the head, they trail the
-head text.
-The
-.Fl width
-argument varies the width of list bodies' left-margins.
+except that the first lines of item bodies are not indented, but follow
+the item heads like in
+.Fl inset
+lists.
.It Fl hyphen
Synonym for
.Fl dash .
.It Fl inset
-List bodies follow the list head.
-The
+Item bodies follow items heads on the same line, using normal inter-word
+spacing.
+Bodies are not indented, and the
.Fl width
argument is ignored.
.It Fl item
-This produces blocks of text.
-The head of list entries must be empty.
-The
+No item heads can be specified, and none are printed.
+Bodies are not indented, and the
.Fl width
argument is ignored.
.It Fl ohang
-List bodies are positioned on the line following the head.
+Item bodies start on the line following item heads and are not indented.
The
.Fl width
argument is ignored.
.It Fl tag
-A list offset by list entry heads. List entry bodies are positioned
-after the head as specified by the
+Item bodies are indented according to the
.Fl width
argument.
+When an item head fits inside the indentation, the item body follows
+this head on the same output line.
+Otherwise, the body starts on the output line following the head.
.El
+.Pp
+Lists may be nested within lists and displays.
+Nesting of
+.Fl column
+and
+.Fl enum
+lists may not be portable.
+.Pp
+See also
+.Sx \&El
+and
+.Sx \&It .
.Ss \&Bo
-Begins a block enclosed by square brackets.
+Begin a block enclosed by square brackets.
Does not have any head arguments.
.Pp
Examples:
-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact
\&.Bo 1 ,
\&.Dv BUFSIZ \&Bc
.Ed
Encloses its arguments in square brackets.
.Pp
Examples:
-.D1 \&.Bq 1 , \&Dv BUFSIZ
+.Dl \&.Bq 1 , \&Dv BUFSIZ
.Pp
.Em Remarks :
this macro is sometimes abused to emulate optional arguments for
See also
.Sx \&Bo .
.Ss \&Brc
-Closes a
+Close a
.Sx \&Bro
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Bro
-Begins a block enclosed by curly braces.
+Begin a block enclosed by curly braces.
Does not have any head arguments.
.Pp
Examples:
-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact
\&.Bro 1 , ... ,
\&.Va n \&Brc
.Ed
Encloses its arguments in curly braces.
.Pp
Examples:
-.D1 \&.Brq 1 , ... , \&Va n
+.Dl \&.Brq 1 , ... , \&Va n
.Pp
See also
.Sx \&Bro .
no argument is provided.
.Pp
Examples:
-.D1 \&.Bsx 1.0
-.D1 \&.Bsx
+.Dl \&.Bsx 1.0
+.Dl \&.Bsx
.Pp
See also
.Sx \&At ,
argument is provided.
.Pp
Examples:
-.D1 \&.Bx 4.4
-.D1 \&.Bx
+.Dl \&.Bx 4.3 Tahoe
+.Dl \&.Bx 4.4
+.Dl \&.Bx
.Pp
See also
.Sx \&At ,
and
.Sx \&Ux .
.Ss \&Cd
-Configuration declaration.
+Kernel configuration declaration.
This denotes strings accepted by
.Xr config 8 .
+It is most often used in section 4 manual pages.
.Pp
Examples:
-.D1 \&.Cd device le0 at scode?
+.Dl \&.Cd device le0 at scode?
.Pp
.Em Remarks :
this macro is commonly abused by using quoted literals to retain
-white-space and align consecutive
+whitespace and align consecutive
.Sx \&Cd
declarations.
This practise is discouraged.
.Ss \&Cm
Command modifiers.
-Useful when specifying configuration options or keys.
+Typically used for fixed strings passed as arguments, unless
+.Sx \&Fl
+is more appropriate.
+Also useful when specifying configuration options or keys.
.Pp
Examples:
-.D1 \&.Cm ControlPath
-.D1 \&.Cm ControlMaster
-.Pp
-See also
-.Sx \&Fl .
+.Dl ".Nm mt Fl f Ar device Cm rewind"
+.Dl ".Nm ps Fl o Cm pid , Ns Cm command"
+.Dl ".Nm dd Cm if= Ns Ar file1 Cm of= Ns Ar file2"
+.Dl ".Cm IdentityFile Pa ~/.ssh/id_rsa"
+.Dl ".Cm LogLevel Dv DEBUG"
.Ss \&D1
One-line indented display.
This is formatted by the default rules and is useful for simple indented
It is followed by a newline.
.Pp
Examples:
-.D1 \&.D1 \&Fl abcdefgh
+.Dl \&.D1 \&Fl abcdefgh
.Pp
See also
.Sx \&Bd
and
.Sx \&Dl .
.Ss \&Db
+Switch debugging mode.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Db Cm on | off
+.Pp
+This macro is ignored by
+.Xr mandoc 1 .
.Ss \&Dc
-Closes a
+Close a
.Sx \&Do
-block. Does not have any tail arguments.
+block.
+Does not have any tail arguments.
.Ss \&Dd
Document date.
This is the mandatory first macro of any
.Nm
manual.
-Its calling syntax is as follows:
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Dd Cm date
+.D1 Pf \. Sx \&Dd Ar month day , year
.Pp
The
-.Cm date
-field may be either
-.Ar $\&Mdocdate$ ,
-which signifies the current manual revision date dictated by
+.Ar month
+is the full English month name, the
+.Ar day
+is an optionally zero-padded numeral, and the
+.Ar year
+is the full four-digit year.
+.Pp
+Other arguments are not portable; the
+.Xr mandoc 1
+utility handles them as follows:
+.Bl -dash -offset 3n -compact
+.It
+To have the date automatically filled in by the
+.Ox
+version of
.Xr cvs 1 ,
-or instead a valid canonical date as specified by
-.Sx Dates .
-If a date does not conform, the current date is used instead.
+the special string
+.Dq $\&Mdocdate$
+can be given as an argument.
+.It
+A few alternative date formats are accepted as well
+and converted to the standard form.
+.It
+If a date string cannot be parsed, it is used verbatim.
+.It
+If no date string is given, the current date is used.
+.El
.Pp
Examples:
-.D1 \&.Dd $\&Mdocdate$
-.D1 \&.Dd $\&Mdocdate: July 21 2007$
-.D1 \&.Dd July 21, 2007
+.Dl \&.Dd $\&Mdocdate$
+.Dl \&.Dd $\&Mdocdate: July 21 2007$
+.Dl \&.Dd July 21, 2007
.Pp
See also
.Sx \&Dt
It is followed by a newline.
.Pp
Examples:
-.D1 \&.Dl % mandoc mdoc.7 | less
+.Dl \&.Dl % mandoc mdoc.7 \e(ba less
.Pp
See also
.Sx \&Bd
and
.Sx \&D1 .
.Ss \&Do
-Begins a block enclosed by double quotes. Does not have any head
-arguments.
+Begin a block enclosed by double quotes.
+Does not have any head arguments.
.Pp
Examples:
-.D1 \&.D1 \&Do April is the cruellest month \&Dc \e(em T.S. Eliot
+.Bd -literal -offset indent -compact
+\&.Do
+April is the cruellest month
+\&.Dc
+\e(em T.S. Eliot
+.Ed
.Pp
See also
.Sx \&Dq .
.Ss \&Dq
-Encloses its arguments in double quotes.
+Encloses its arguments in
+.Dq typographic
+double-quotes.
.Pp
Examples:
.Bd -literal -offset indent -compact
.Ed
.Pp
See also
+.Sx \&Qq ,
+.Sx \&Sq ,
+and
.Sx \&Do .
.Ss \&Dt
Document title.
This is the mandatory second macro of any
.Nm
file.
-Its calling syntax is as follows:
-.Pp
-.D1 \. Ns Sx \&Dt Cm title section Op Cm volume | arch
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Dt
+.Oo
+.Ar title
+.Oo
+.Ar section
+.Op Ar volume | arch
+.Oc
+.Oc
+.Ed
.Pp
Its arguments are as follows:
.Bl -tag -width Ds -offset Ds
-.It Cm title
-The document's title (name).
-This should be capitalised and is required.
-.It Cm section
+.It Ar title
+The document's title (name), defaulting to
+.Dq UNKNOWN
+if unspecified.
+It should be capitalised.
+.It Ar section
The manual section.
This may be one of
.Ar 1
or
.Ar paper
.Pq paper .
-It is also required and should correspond to the manual's filename
-suffix.
-.It Cm volume
+It should correspond to the manual's filename suffix and defaults to
+.Dq 1
+if unspecified.
+.It Ar volume
This overrides the volume inferred from
.Ar section .
This field is optional, and if specified, must be one of
or
.Ar CON
.Pq contributed manuals .
-.It Cm arch
+.It Ar arch
This specifies a specific relevant architecture.
If
-.Cm volume
+.Ar volume
is not provided, it may be used in its place, else it may be used
subsequent that.
It, too, is optional.
.Ar luna88k ,
.Ar mac68k ,
.Ar macppc ,
+.Ar mips64 ,
.Ar mvme68k ,
.Ar mvme88k ,
.Ar mvmeppc ,
.El
.Pp
Examples:
-.D1 \&.Dt FOO 1
-.D1 \&.Dt FOO 4 KM
-.D1 \&.Dt FOO 9 i386
-.D1 \&.Dt FOO 9 KM i386
+.Dl \&.Dt FOO 1
+.Dl \&.Dt FOO 4 KM
+.Dl \&.Dt FOO 9 i386
.Pp
See also
.Sx \&Dd
and
.Sx \&Os .
.Ss \&Dv
-Defined variables such as preprocessor constants.
+Defined variables such as preprocessor constants, constant symbols,
+enumeration values, and so on.
.Pp
Examples:
-.D1 \&.Dv BUFSIZ
-.D1 \&.Dv STDOUT_FILENO
+.Dl \&.Dv NULL
+.Dl \&.Dv BUFSIZ
+.Dl \&.Dv STDOUT_FILENO
.Pp
See also
-.Sx \&Er .
+.Sx \&Er
+and
+.Sx \&Ev
+for special-purpose constants and
+.Sx \&Va
+for variable symbols.
.Ss \&Dx
Format the DragonFly BSD version provided as an argument, or a default
value if no argument is provided.
.Pp
Examples:
-.D1 \&.Dx 2.4.1
-.D1 \&.Dx
+.Dl \&.Dx 2.4.1
+.Dl \&.Dx
.Pp
See also
.Sx \&At ,
and
.Sx \&Ux .
.Ss \&Ec
+Close a scope started by
+.Sx \&Eo .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ec Op Ar TERM
+.Pp
+The
+.Ar TERM
+argument is used as the enclosure tail, for example, specifying \e(rq
+will emulate
+.Sx \&Dc .
.Ss \&Ed
+End a display context started by
+.Sx \&Bd .
.Ss \&Ef
+End a font mode context started by
+.Sx \&Bf .
.Ss \&Ek
+End a keep context started by
+.Sx \&Bk .
.Ss \&El
+End a list context started by
+.Sx \&Bl .
+.Pp
+See also
+.Sx \&Bl
+and
+.Sx \&It .
.Ss \&Em
-Denotes text that should be emphasised.
+Denotes text that should be
+.Em emphasised .
Note that this is a presentation term and should not be used for
stylistically decorating technical terms.
+Depending on the output device, this is usually represented
+using an italic font or underlined characters.
.Pp
Examples:
-.D1 \&.Em Warnings!
-.D1 \&.Em Remarks :
+.Dl \&.Em Warnings!
+.Dl \&.Em Remarks :
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Li ,
+.Sx \&No ,
+and
+.Sx \&Sy .
.Ss \&En
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .
.Ss \&Eo
+An arbitrary enclosure.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Eo Op Ar TERM
+.Pp
+The
+.Ar TERM
+argument is used as the enclosure head, for example, specifying \e(lq
+will emulate
+.Sx \&Do .
.Ss \&Er
-Display error constants.
+Error constants for definitions of the
+.Va errno
+libc global variable.
+This is most often used in section 2 and 3 manual pages.
.Pp
Examples:
-.D1 \&.Er EPERM
-.D1 \&.Er ENOENT
+.Dl \&.Er EPERM
+.Dl \&.Er ENOENT
.Pp
See also
-.Sx \&Dv .
+.Sx \&Dv
+for general constants.
.Ss \&Es
+This macro is obsolete and not implemented.
.Ss \&Ev
Environmental variables such as those specified in
.Xr environ 7 .
.Pp
Examples:
-.D1 \&.Ev DISPLAY
-.D1 \&.Ev PATH
+.Dl \&.Ev DISPLAY
+.Dl \&.Ev PATH
+.Pp
+See also
+.Sx \&Dv
+for general constants.
.Ss \&Ex
-Inserts text regarding a utility's exit values.
-This macro must have first the
-.Fl std
-argument specified, then an optional
-.Ar utility .
+Insert a standard sentence regarding command exit values of 0 on success
+and >0 on failure.
+This is most often used in section 1, 6, and 8 manual pages.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ex Fl std Op Ar utility ...
+.Pp
If
.Ar utility
-is not provided, the document's name as stipulated in
+is not specified, the document's name set by
.Sx \&Nm
-is provided.
+is used.
+Multiple
+.Ar utility
+arguments are treated as separate utilities.
+.Pp
+See also
+.Sx \&Rv .
.Ss \&Fa
+Function argument.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Fa
+.Op Cm argtype
+.Cm argname
+.Ed
+.Pp
+This may be invoked for names with or without the corresponding type.
+It is also used to specify the field name of a structure.
+Most often, the
+.Sx \&Fa
+macro is used in the
+.Em SYNOPSIS
+within
+.Sx \&Fo
+section when documenting multi-line function prototypes.
+If invoked with multiple arguments, the arguments are separated by a
+comma.
+Furthermore, if the following macro is another
+.Sx \&Fa ,
+the last argument will also have a trailing comma.
+.Pp
+Examples:
+.Dl \&.Fa \(dqconst char *p\(dq
+.Dl \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq
+.Dl \&.Fa foo
+.Pp
+See also
+.Sx \&Fo .
.Ss \&Fc
+End a function context started by
+.Sx \&Fo .
.Ss \&Fd
+Historically used to document include files.
+This usage has been deprecated in favour of
+.Sx \&In .
+Do not use this macro.
+.Pp
+See also
+.Sx MANUAL STRUCTURE
+and
+.Sx \&In .
.Ss \&Fl
-Command-line flag.
+Command-line flag or option.
Used when listing arguments to command-line utilities.
Prints a fixed-width hyphen
.Sq \-
output.
.Pp
Examples:
-.D1 \&.Fl a b c
-.D1 \&.Fl \&Pf a b
-.D1 \&.Fl
-.D1 \&.Op \&Fl o \&Ns \&Ar file
+.Dl ".Fl R Op Fl H | L | P"
+.Dl ".Op Fl 1AaCcdFfgHhikLlmnopqRrSsTtux"
+.Dl ".Fl type Cm d Fl name Pa CVS"
+.Dl ".Fl Ar signal_number"
+.Dl ".Fl o Fl"
.Pp
See also
.Sx \&Cm .
.Ss \&Fn
+A function name.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Ns Sx \&Fn
+.Op Ar functype
+.Ar funcname
+.Op Oo Ar argtype Oc Ar argname
+.Ed
+.Pp
+Function arguments are surrounded in parenthesis and
+are delimited by commas.
+If no arguments are specified, blank parenthesis are output.
+In the
+.Em SYNOPSIS
+section, this macro starts a new output line,
+and a blank line is automatically inserted between function definitions.
+.Pp
+Examples:
+.Dl \&.Fn \*qint funcname\*q \*qint arg0\*q \*qint arg1\*q
+.Dl \&.Fn funcname \*qint arg0\*q
+.Dl \&.Fn funcname arg0
+.Pp
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+When referring to a function documented in another manual page, use
+.Sx \&Xr
+instead.
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fo ,
+and
+.Sx \&Ft .
.Ss \&Fo
+Begin a function block.
+This is a multi-line version of
+.Sx \&Fn .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Fo Ar funcname
+.Pp
+Invocations usually occur in the following context:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Ft Ar functype
+.br
+.Pf \. Sx \&Fo Ar funcname
+.br
+.Pf \. Sx \&Fa Oo Ar argtype Oc Ar argname
+.br
+\&.\.\.
+.br
+.Pf \. Sx \&Fc
+.Ed
+.Pp
+A
+.Sx \&Fo
+scope is closed by
+.Sx \&Fc .
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fa ,
+.Sx \&Fc ,
+and
+.Sx \&Ft .
.Ss \&Fr
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .
+.Pp
+It was used to show function return values.
+The syntax was:
+.Pp
+.Dl Pf . Sx \&Fr Ar value
.Ss \&Ft
+A function type.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ft Ar functype
+.Pp
+In the
+.Em SYNOPSIS
+section, a new output line is started after this macro.
+.Pp
+Examples:
+.Dl \&.Ft int
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fn ,
+and
+.Sx \&Fo .
.Ss \&Fx
-Format the FreeBSD version provided as an argument, or a default value
+Format the
+.Fx
+version provided as an argument, or a default value
if no argument is provided.
.Pp
Examples:
-.D1 \&.Fx 7.1
-.D1 \&.Fx
+.Dl \&.Fx 7.1
+.Dl \&.Fx
.Pp
See also
.Sx \&At ,
and
.Sx \&Ux .
.Ss \&Hf
+This macro is not implemented in
+.Xr mandoc 1 .
+.Pp
+It was used to include the contents of a (header) file literally.
+The syntax was:
+.Pp
+.Dl Pf . Sx \&Hf Ar filename
.Ss \&Ic
+Designate an internal or interactive command.
+This is similar to
+.Sx \&Cm
+but used for instructions rather than values.
+.Pp
+Examples:
+.Dl \&.Ic :wq
+.Dl \&.Ic hash
+.Dl \&.Ic alias
+.Pp
+Note that using
+.Sx \&Bd Fl literal
+or
+.Sx \&D1
+is preferred for displaying code; the
+.Sx \&Ic
+macro is used when referring to specific instructions.
.Ss \&In
+An
+.Dq include
+file.
+When invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section, the argument is displayed in angle brackets
+and preceded by
+.Dq #include ,
+and a blank line is inserted in front if there is a preceding
+function declaration.
+This is most often used in section 2, 3, and 9 manual pages.
+.Pp
+Examples:
+.Dl \&.In sys/types.h
+.Pp
+See also
+.Sx MANUAL STRUCTURE .
.Ss \&It
+A list item.
+The syntax of this macro depends on the list type.
+.Pp
+Lists
+of type
+.Fl hang ,
+.Fl ohang ,
+.Fl inset ,
+and
+.Fl diag
+have the following syntax:
+.Pp
+.D1 Pf \. Sx \&It Ar args
+.Pp
+Lists of type
+.Fl bullet ,
+.Fl dash ,
+.Fl enum ,
+.Fl hyphen
+and
+.Fl item
+have the following syntax:
+.Pp
+.D1 Pf \. Sx \&It
+.Pp
+with subsequent lines interpreted within the scope of the
+.Sx \&It
+until either a closing
+.Sx \&El
+or another
+.Sx \&It .
+.Pp
+The
+.Fl tag
+list has the following syntax:
+.Pp
+.D1 Pf \. Sx \&It Op Cm args
+.Pp
+Subsequent lines are interpreted as with
+.Fl bullet
+and family.
+The line arguments correspond to the list's left-hand side; body
+arguments correspond to the list's contents.
+.Pp
+The
+.Fl column
+list is the most complicated.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...
+.D1 Pf \. Sx \&It Ar cell Op Sx \&Ta Ar cell ...
+.Pp
+The arguments consist of one or more lines of text and macros
+representing a complete table line.
+Cells within the line are delimited by tabs or by the special
+.Sx \&Ta
+block macro.
+The tab cell delimiter may only be used within the
+.Sx \&It
+line itself; on following lines, only the
+.Sx \&Ta
+macro can be used to delimit cells, and
+.Sx \&Ta
+is only recognized as a macro when called by other macros,
+not as the first macro on a line.
+.Pp
+Note that quoted strings may span tab-delimited cells on an
+.Sx \&It
+line.
+For example,
+.Pp
+.Dl .It \(dqcol1 ; <TAB> col2 ;\(dq \&;
+.Pp
+will preserve the semicolon whitespace except for the last.
+.Pp
+See also
+.Sx \&Bl .
.Ss \&Lb
+Specify a library.
+The syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Lb Ar library
+.Pp
+The
+.Ar library
+parameter may be a system library, such as
+.Cm libz
+or
+.Cm libpam ,
+in which case a small library description is printed next to the linker
+invocation; or a custom library, in which case the library name is
+printed in quotes.
+This is most commonly used in the
+.Em SYNOPSIS
+section as described in
+.Sx MANUAL STRUCTURE .
+.Pp
+Examples:
+.Dl \&.Lb libz
+.Dl \&.Lb mdoc
.Ss \&Li
+Denotes text that should be in a
+.Li literal
+font mode.
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Pp
+On terminal output devices, this is often indistinguishable from
+normal text.
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Em ,
+.Sx \&No ,
+and
+.Sx \&Sy .
.Ss \&Lk
Format a hyperlink.
-The calling syntax is as follows:
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Lk Cm uri Op Cm name
+.D1 Pf \. Sx \&Lk Ar uri Op Ar name
.Pp
Examples:
-.D1 \&.Lk http://bsd.lv "The BSD.lv Project"
-.D1 \&.Lk http://bsd.lv
+.Dl \&.Lk http://bsd.lv \*qThe BSD.lv Project\*q
+.Dl \&.Lk http://bsd.lv
.Pp
See also
.Sx \&Mt .
.Ss \&Lp
+Synonym for
+.Sx \&Pp .
.Ss \&Ms
+Display a mathematical symbol.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ms Ar symbol
+.Pp
+Examples:
+.Dl \&.Ms sigma
+.Dl \&.Ms aleph
.Ss \&Mt
+Format a
+.Dq mailto:
+hyperlink.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Mt Ar address
+.Pp
+Examples:
+.Dl \&.Mt discuss@manpages.bsd.lv
.Ss \&Nd
+A one line description of the manual's content.
+This may only be invoked in the
+.Em SYNOPSIS
+section subsequent the
+.Sx \&Nm
+macro.
+.Pp
+Examples:
+.Dl Pf . Sx \&Nd mdoc language reference
+.Dl Pf . Sx \&Nd format and display UNIX manuals
+.Pp
+The
+.Sx \&Nd
+macro technically accepts child macros and terminates with a subsequent
+.Sx \&Sh
+invocation.
+Do not assume this behaviour: some
+.Xr whatis 1
+database generators are not smart enough to parse more than the line
+arguments and will display macros verbatim.
+.Pp
+See also
+.Sx \&Nm .
.Ss \&Nm
+The name of the manual page, or \(em in particular in section 1, 6,
+and 8 pages \(em of an additional command or feature documented in
+the manual page.
+When first invoked, the
+.Sx \&Nm
+macro expects a single argument, the name of the manual page.
+Usually, the first invocation happens in the
+.Em NAME
+section of the page.
+The specified name will be remembered and used whenever the macro is
+called again without arguments later in the page.
+The
+.Sx \&Nm
+macro uses
+.Sx Block full-implicit
+semantics when invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section; otherwise, it uses ordinary
+.Sx In-line
+semantics.
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Sh SYNOPSIS
+\&.Nm cat
+\&.Op Fl benstuv
+\&.Op Ar
+.Ed
+.Pp
+In the
+.Em SYNOPSIS
+of section 2, 3 and 9 manual pages, use the
+.Sx \&Fn
+macro rather than
+.Sx \&Nm
+to mark up the name of the manual page.
.Ss \&No
+Normal text.
+Closes the scope of any preceding in-line macro.
+When used after physical formatting macros like
+.Sx \&Em
+or
+.Sx \&Sy ,
+switches back to the standard font face and weight.
+Can also be used to embed plain text strings in macro lines
+using semantic annotation macros.
+.Pp
+Examples:
+.Dl ".Em italic , Sy bold , No and roman"
+.Pp
+.Bd -literal -offset indent -compact
+\&.Sm off
+\&.Cm :C No / Ar pattern No / Ar replacement No /
+\&.Sm on
+.Ed
+.Pp
+See also
+.Sx \&Em ,
+.Sx \&Li ,
+and
+.Sx \&Sy .
.Ss \&Ns
+Suppress a space between the output of the preceding macro
+and the following text or macro.
+Following invocation, input is interpreted as normal text
+just like after an
+.Sx \&No
+macro.
+.Pp
+This has no effect when invoked at the start of a macro line.
+.Pp
+Examples:
+.Dl ".Ar name Ns = Ns Ar value"
+.Dl ".Cm :M Ns Ar pattern"
+.Dl ".Fl o Ns Ar output"
+.Pp
+See also
+.Sx \&No
+and
+.Sx \&Sm .
.Ss \&Nx
-Format the NetBSD version provided as an argument, or a default value if
+Format the
+.Nx
+version provided as an argument, or a default value if
no argument is provided.
.Pp
Examples:
-.D1 \&.Nx 5.01
-.D1 \&.Nx
+.Dl \&.Nx 5.01
+.Dl \&.Nx
.Pp
See also
.Sx \&At ,
and
.Sx \&Ux .
.Ss \&Oc
+Close multi-line
+.Sx \&Oo
+context.
.Ss \&Oo
+Multi-line version of
+.Sx \&Op .
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.Oo
+\&.Op Fl flag Ns Ar value
+\&.Oc
+.Ed
.Ss \&Op
+Optional part of a command line.
+Prints the argument(s) in brackets.
+This is most often used in the
+.Em SYNOPSIS
+section of section 1 and 8 manual pages.
+.Pp
+Examples:
+.Dl \&.Op \&Fl a \&Ar b
+.Dl \&.Op \&Ar a | b
+.Pp
+See also
+.Sx \&Oo .
.Ss \&Os
Document operating system version.
This is the mandatory third macro of
any
.Nm
-file. Its calling syntax is as follows:
+file.
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Os Op Cm system
+.D1 Pf \. Sx \&Os Op Ar system Op Ar version
.Pp
The optional
-.Cm system
+.Ar system
parameter specifies the relevant operating system or environment.
Left unspecified, it defaults to the local operating system version.
This is the suggested form.
.Pp
Examples:
-.D1 \&.Os
-.D1 \&.Os KTH/CSC/TCS
-.D1 \&.Os BSD 4.3
+.Dl \&.Os
+.Dl \&.Os KTH/CSC/TCS
+.Dl \&.Os BSD 4.3
.Pp
See also
.Sx \&Dd
and
.Sx \&Dt .
.Ss \&Ot
-Unknown usage.
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .
.Pp
-.Em Remarks :
-this macro has been deprecated.
+Historical
+.Xr mdoc 7
+packages described it as
+.Dq "old function type (FORTRAN)" .
.Ss \&Ox
-Format the OpenBSD version provided as an argument, or a default value
+Format the
+.Ox
+version provided as an argument, or a default value
if no argument is provided.
.Pp
Examples:
-.D1 \&.Ox 4.5
-.D1 \&.Ox
+.Dl \&.Ox 4.5
+.Dl \&.Ox
.Pp
See also
.Sx \&At ,
and
.Sx \&Ux .
.Ss \&Pa
+An absolute or relative file system path, or a file or directory name.
+If an argument is not provided, the character
+.Sq \(ti
+is used as a default.
+.Pp
+Examples:
+.Dl \&.Pa /usr/bin/mandoc
+.Dl \&.Pa /usr/share/man/man7/mdoc.7
+.Pp
+See also
+.Sx \&Lk .
.Ss \&Pc
+Close parenthesised context opened by
+.Sx \&Po .
.Ss \&Pf
+Removes the space between its argument
+.Pq Dq prefix
+and the following macro.
+Its syntax is as follows:
+.Pp
+.D1 .Pf Ar prefix macro arguments ...
+.Pp
+This is equivalent to:
+.Pp
+.D1 .No Ar prefix No \&Ns Ar macro arguments ...
+.Pp
+Examples:
+.Dl ".Pf $ Ar variable_name"
+.Dl ".Pf 0x Ar hex_digits"
+.Pp
+See also
+.Sx \&Ns
+and
+.Sx \&Sm .
.Ss \&Po
+Multi-line version of
+.Sx \&Pq .
.Ss \&Pp
+Break a paragraph.
+This will assert vertical space between prior and subsequent macros
+and/or text.
+.Pp
+Paragraph breaks are not needed before or after
+.Sx \&Sh
+or
+.Sx \&Ss
+macros or before displays
+.Pq Sx \&Bd
+or lists
+.Pq Sx \&Bl
+unless the
+.Fl compact
+flag is given.
.Ss \&Pq
+Parenthesised enclosure.
+.Pp
+See also
+.Sx \&Po .
.Ss \&Qc
+Close quoted context opened by
+.Sx \&Qo .
.Ss \&Ql
+Format a single-quoted literal.
+See also
+.Sx \&Qq
+and
+.Sx \&Sq .
.Ss \&Qo
+Multi-line version of
+.Sx \&Qq .
.Ss \&Qq
+Encloses its arguments in
+.Qq typewriter
+double-quotes.
+Consider using
+.Sx \&Dq .
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Sq ,
+and
+.Sx \&Qo .
.Ss \&Re
-Closes a
+Close an
.Sx \&Rs
block.
Does not have any tail arguments.
.Ss \&Rs
-Begins a bibliographic
+Begin a bibliographic
.Pq Dq reference
block.
Does not have any head arguments.
.Sx \&%Q ,
.Sx \&%R ,
.Sx \&%T ,
+.Sx \&%U ,
and
.Sx \&%V
child macros (at least one must be specified).
before the rendered output, else the block continues on the current
line.
.Ss \&Rv
+Insert a standard sentence regarding a function call's return value of 0
+on success and \-1 on error, with the
+.Va errno
+libc global variable set on error.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Rv Fl std Op Ar function ...
+.Pp
+If
+.Ar function
+is not specified, the document's name set by
+.Sx \&Nm
+is used.
+Multiple
+.Ar function
+arguments are treated as separate functions.
+.Pp
+See also
+.Sx \&Ex .
.Ss \&Sc
+Close single-quoted context opened by
+.Sx \&So .
.Ss \&Sh
+Begin a new section.
+For a list of conventional manual sections, see
+.Sx MANUAL STRUCTURE .
+These sections should be used unless it's absolutely necessary that
+custom sections be used.
+.Pp
+Section names should be unique so that they may be keyed by
+.Sx \&Sx .
+Although this macro is parsed, it should not consist of child node or it
+may not be linked with
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Ss ,
+and
+.Sx \&Sx .
.Ss \&Sm
+Switches the spacing mode for output generated from macros.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Sm Cm on | off
+.Pp
+By default, spacing is
+.Cm on .
+When switched
+.Cm off ,
+no white space is inserted between macro arguments and between the
+output generated from adjacent macros, but text lines
+still get normal spacing between words and sentences.
.Ss \&So
+Multi-line version of
+.Sx \&Sq .
.Ss \&Sq
+Encloses its arguments in
+.Sq typewriter
+single-quotes.
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Qq ,
+and
+.Sx \&So .
.Ss \&Ss
+Begin a new subsection.
+Unlike with
+.Sx \&Sh ,
+there is no convention for the naming of subsections.
+Except
+.Em DESCRIPTION ,
+the conventional sections described in
+.Sx MANUAL STRUCTURE
+rarely have subsections.
+.Pp
+Sub-section names should be unique so that they may be keyed by
+.Sx \&Sx .
+Although this macro is parsed, it should not consist of child node or it
+may not be linked with
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Sh ,
+and
+.Sx \&Sx .
.Ss \&St
+Replace an abbreviation for a standard with the full form.
+The following standards are recognised:
+.Pp
+.Bl -tag -width "-p1003.1g-2000X" -compact
+.It \-p1003.1-88
+.St -p1003.1-88
+.It \-p1003.1-90
+.St -p1003.1-90
+.It \-p1003.1-96
+.St -p1003.1-96
+.It \-p1003.1-2001
+.St -p1003.1-2001
+.It \-p1003.1-2004
+.St -p1003.1-2004
+.It \-p1003.1-2008
+.St -p1003.1-2008
+.It \-p1003.1
+.St -p1003.1
+.It \-p1003.1b
+.St -p1003.1b
+.It \-p1003.1b-93
+.St -p1003.1b-93
+.It \-p1003.1c-95
+.St -p1003.1c-95
+.It \-p1003.1g-2000
+.St -p1003.1g-2000
+.It \-p1003.1i-95
+.St -p1003.1i-95
+.It \-p1003.2-92
+.St -p1003.2-92
+.It \-p1003.2a-92
+.St -p1003.2a-92
+.It \-p1387.2-95
+.St -p1387.2-95
+.It \-p1003.2
+.St -p1003.2
+.It \-p1387.2
+.St -p1387.2
+.It \-isoC
+.St -isoC
+.It \-isoC-90
+.St -isoC-90
+.It \-isoC-amd1
+.St -isoC-amd1
+.It \-isoC-tcor1
+.St -isoC-tcor1
+.It \-isoC-tcor2
+.St -isoC-tcor2
+.It \-isoC-99
+.St -isoC-99
+.It \-iso9945-1-90
+.St -iso9945-1-90
+.It \-iso9945-1-96
+.St -iso9945-1-96
+.It \-iso9945-2-93
+.St -iso9945-2-93
+.It \-ansiC
+.St -ansiC
+.It \-ansiC-89
+.St -ansiC-89
+.It \-ansiC-99
+.St -ansiC-99
+.It \-ieee754
+.St -ieee754
+.It \-iso8802-3
+.St -iso8802-3
+.It \-ieee1275-94
+.St -ieee1275-94
+.It \-xpg3
+.St -xpg3
+.It \-xpg4
+.St -xpg4
+.It \-xpg4.2
+.St -xpg4.2
+.It \-xpg4.3
+.St -xpg4.3
+.It \-xbd5
+.St -xbd5
+.It \-xcu5
+.St -xcu5
+.It \-xsh5
+.St -xsh5
+.It \-xns5
+.St -xns5
+.It \-xns5.2
+.St -xns5.2
+.It \-xns5.2d2.0
+.St -xns5.2d2.0
+.It \-xcurses4.2
+.St -xcurses4.2
+.It \-susv2
+.St -susv2
+.It \-susv3
+.St -susv3
+.It \-svid4
+.St -svid4
+.El
.Ss \&Sx
+Reference a section or subsection in the same manual page.
+The referenced section or subsection name must be identical to the
+enclosed argument, including whitespace.
+.Pp
+Examples:
+.Dl \&.Sx MANUAL STRUCTURE
+.Pp
+See also
+.Sx \&Sh
+and
+.Sx \&Ss .
.Ss \&Sy
+Format enclosed arguments in symbolic
+.Pq Dq boldface .
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Em ,
+.Sx \&Li ,
+and
+.Sx \&No .
+.Ss \&Ta
+Table cell separator in
+.Sx \&Bl Fl column
+lists; can only be used below
+.Sx \&It .
.Ss \&Tn
+Format a tradename.
+.Pp
+Since this macro is often implemented to use a small caps font,
+it has historically been used for acronyms (like ASCII) as well.
+Such usage is not recommended because it would use the same macro
+sometimes for semantical annotation, sometimes for physical formatting.
+.Pp
+Examples:
+.Dl \&.Tn IBM
.Ss \&Ud
+Prints out
+.Dq currently under development.
.Ss \&Ux
Format the UNIX name.
Accepts no argument.
.Pp
Examples:
-.D1 \&.Ux
+.Dl \&.Ux
.Pp
See also
.Sx \&At ,
and
.Sx \&Ox .
.Ss \&Va
+A variable name.
+.Pp
+Examples:
+.Dl \&.Va foo
+.Dl \&.Va const char *bar ;
.Ss \&Vt
A variable type.
-This is also used for indicating global variables in the SYNOPSIS
+This is also used for indicating global variables in the
+.Em SYNOPSIS
section, in which case a variable name is also specified.
Note that it accepts
.Sx Block partial-implicit
-syntax when invoked as the first macro in the SYNOPSIS section, else it
-accepts ordinary
+syntax when invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section, else it accepts ordinary
.Sx In-line
syntax.
+In the former case, this macro starts a new output line,
+and a blank line is inserted in front if there is a preceding
+function definition or include directive.
.Pp
Note that this should not be confused with
.Sx \&Ft ,
which is used for function return types.
.Pp
Examples:
-.D1 \&.Vt unsigned char
-.D1 \&.Vt extern const char * const sys_signame[] ;
+.Dl \&.Vt unsigned char
+.Dl \&.Vt extern const char * const sys_signame[] \&;
.Pp
See also
-.Sx \&Ft
+.Sx MANUAL STRUCTURE
and
.Sx \&Va .
.Ss \&Xc
Close a scope opened by
.Sx \&Xo .
.Ss \&Xo
-Open an extension scope.
-This macro originally existed to extend the 9-argument limit of troff;
-since this limit has been lifted, the macro has been deprecated.
+Extend the header of an
+.Sx \&It
+macro or the body of a partial-implicit block macro
+beyond the end of the input line.
+This macro originally existed to work around the 9-argument limit
+of historic
+.Xr roff 7 .
.Ss \&Xr
Link to another manual
.Pq Qq cross-reference .
-Its calling syntax is
+Its syntax is as follows:
.Pp
-.D1 \. Ns Sx \&Xr Cm name section
+.D1 Pf \. Sx \&Xr Ar name section
.Pp
The
-.Cm name
+.Ar name
and
-.Cm section
+.Ar section
are the name and section of the linked manual.
If
-.Cm section
+.Ar section
is followed by non-punctuation, an
.Sx \&Ns
is inserted into the token stream.
This behaviour is for compatibility with
-.Xr groff 1 .
+GNU troff.
.Pp
Examples:
-.D1 \&.Xr mandoc 1
-.D1 \&.Xr mandoc 1 ;
-.D1 \&.Xr mandoc 1 \&Ns s behaviour
+.Dl \&.Xr mandoc 1
+.Dl \&.Xr mandoc 1 \&;
+.Dl \&.Xr mandoc 1 \&Ns s behaviour
.Ss \&br
+Emits a line-break.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+.Pp
+Consider using
+.Sx \&Pp
+in the event of natural paragraph breaks.
.Ss \&sp
+Emits vertical space.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&sp Op Ar height
+.Pp
+The
+.Ar height
+argument must be formatted as described in
+.Sx Scaling Widths .
+If unspecified,
+.Sx \&sp
+asserts a single vertical space.
.Sh COMPATIBILITY
This section documents compatibility between mandoc and other other
troff implementations, at this time limited to GNU troff
.Pq Qq groff .
The term
.Qq historic groff
-refers to groff versions before the
+refers to groff versions before 1.17,
+which featured a significant update of the
.Pa doc.tmac
-file re-write
-.Pq somewhere between 1.15 and 1.19 .
+file.
.Pp
Heirloom troff, the other significant troff implementation accepting
\-mdoc, is similar to historic groff.
.Pp
+The following problematic behaviour is found in groff:
+.ds hist (Historic groff only.)
+.Pp
.Bl -dash -compact
.It
-The comment syntax
-.Sq \e."
-is no longer accepted.
+Display macros
+.Po
+.Sx \&Bd ,
+.Sx \&Dl ,
+and
+.Sx \&D1
+.Pc
+may not be nested.
+\*[hist]
.It
-In groff, the
-.Sx \&Pa
-macro does not format its arguments when used in the FILES section under
-certain list types.
-mandoc does.
+.Sx \&At
+with unknown arguments produces no output at all.
+\*[hist]
+Newer groff and mandoc print
+.Qq AT&T UNIX
+and the arguments.
.It
-Historic groff does not print a dash for empty
-.Sx \&Fl
-arguments.
-mandoc and newer groff implementations do.
+.Sx \&Bl Fl column
+does not recognize trailing punctuation characters when they immediately
+precede tabulator characters, but treats them as normal text and
+outputs a space before them.
.It
-groff behaves irregularly when specifying
-.Sq \ef
-.Sx Text Decoration
-within line-macro scopes.
-mandoc follows a consistent system.
+.Sx \&Bd Fl ragged compact
+does not start a new line.
+\*[hist]
.It
-In mandoc, negative scaling units are truncated to zero; groff would
-move to prior lines.
-Furthermore, the
-.Sq f
-scaling unit, while accepted, is rendered as the default unit.
+.Sx \&Dd
+with non-standard arguments behaves very strangely.
+When there are three arguments, they are printed verbatim.
+Any other number of arguments is replaced by the current date,
+but without any arguments the string
+.Dq Epoch
+is printed.
.It
-In quoted literals, groff allowed pair-wise double-quotes to produce a
-standalone double-quote in formatted output.
-This idiosyncratic behaviour is not applicable in mandoc.
+.Sx \&Fl
+does not print a dash for an empty argument.
+\*[hist]
.It
-Display types
-.Sx \&Bd
-.Fl center
-and
-.Fl right
-are aliases for
-.Fl left
-in manodc. Furthermore, the
-.Fl file Ar file
-argument is ignored.
-Lastly, since text is not right-justified in mandoc (or even groff),
-.Fl ragged
-and
-.Fl filled
-are aliases, as are
-.Fl literal
-and
-.Fl unfilled .
+.Sx \&Fn
+does not start a new line unless invoked as the line macro in the
+.Em SYNOPSIS
+section.
+\*[hist]
.It
-Historic groff has many un-callable macros.
-Most of these (excluding some block-level macros) are now callable.
+.Sx \&Fo
+with
+.Pf non- Sx \&Fa
+children causes inconsistent spacing between arguments.
+In mandoc, a single space is always inserted between arguments.
.It
-The vertical bar
-.Sq \(ba
-made historic groff
-.Qq go orbital
-but has been a proper delimiter since then.
+.Sx \&Ft
+in the
+.Em SYNOPSIS
+causes inconsistent vertical spacing, depending on whether a prior
+.Sx \&Fn
+has been invoked.
+See
+.Sx \&Ft
+and
+.Sx \&Fn
+for the normalised behaviour in mandoc.
.It
-.Sx \&It Fl nested
-is assumed for all lists (it wasn't in historic groff): any list may be
-nested and
+.Sx \&In
+ignores additional arguments and is not treated specially in the
+.Em SYNOPSIS .
+\*[hist]
+.It
+.Sx \&It
+sometimes requires a
+.Fl nested
+flag.
+\*[hist]
+In new groff and mandoc, any list may be nested by default and
.Fl enum
lists will restart the sequence only for the sub-list.
.It
-Some manuals use
.Sx \&Li
-incorrectly by following it with a reserved character and expecting the
-delimiter to render.
-This is not supported in mandoc.
+followed by a delimiter is incorrectly used in some manuals
+instead of properly quoting that character, which sometimes works with
+historic groff.
.It
-In groff, the
-.Sx \&Fo
-macro only produces the first parameter.
-This is not the case in mandoc.
+.Sx \&Lk
+only accepts a single link-name argument; the remainder is misformatted.
.It
-In groff, the
-.Sx \&Cd ,
-.Sx \&Er ,
+.Sx \&Pa
+does not format its arguments when used in the FILES section under
+certain list types.
+.It
+.Sx \&Ta
+can only be called by other macros, but not at the beginning of a line.
+.It
+.Sx \&%C
+is not implemented.
+.It
+Historic groff only allows up to eight or nine arguments per macro input
+line, depending on the exact situation.
+Providing more arguments causes garbled output.
+The number of arguments on one input line is not limited with mandoc.
+.It
+Historic groff has many un-callable macros.
+Most of these (excluding some block-level macros) are callable
+in new groff and mandoc.
+.It
+.Sq \(ba
+(vertical bar) is not fully supported as a delimiter.
+\*[hist]
+.It
+.Sq \ef
+.Pq font face
and
-.Sx \&Ex
-macros were stipulated only to occur in certain manual sections.
-mandoc does not have these restrictions.
+.Sq \ef
+.Pq font family face
+.Sx Text Decoration
+escapes behave irregularly when specified within line-macro scopes.
.It
-Newer groff and mandoc print
-.Qq AT&T UNIX
-prior to unknown arguments of
-.Sx \&At ;
-older groff did nothing.
+Negative scaling units return to prior lines.
+Instead, mandoc truncates them to zero.
+.El
+.Pp
+The following features are unimplemented in mandoc:
+.Pp
+.Bl -dash -compact
+.It
+.Sx \&Bd
+.Fl file Ar file .
+.It
+.Sx \&Bd
+.Fl offset Ar center
+and
+.Fl offset Ar right .
+Groff does not implement centered and flush-right rendering either,
+but produces large indentations.
+.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
+In quoted literals, groff allows pairwise double-quotes to produce a
+standalone double-quote in formatted output.
+This is not supported by mandoc.
.El
.Sh SEE ALSO
+.Xr man 1 ,
.Xr mandoc 1 ,
-.Xr mandoc_char 7
+.Xr eqn 7 ,
+.Xr man 7 ,
+.Xr mandoc_char 7 ,
+.Xr roff 7 ,
+.Xr tbl 7
+.Sh HISTORY
+The
+.Nm
+language first appeared as a troff macro package in
+.Bx 4.4 .
+It was later significantly updated by Werner Lemberg and Ruslan Ermilov
+in groff-1.17.
+The standalone implementation that is part of the
+.Xr mandoc 1
+utility written by Kristaps Dzonsons appeared in
+.Ox 4.6 .
.Sh AUTHORS
The
.Nm
reference was written by
-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
-.\"
-.\" XXX: this really isn't the place for these caveats.
-.\" .
-.\" .
-.\" .Sh CAVEATS
-.\" There are many ambiguous parts of mdoc.
-.\" .
-.\" .Pp
-.\" .Bl -dash -compact
-.\" .It
-.\" .Sq \&Fa
-.\" should be
-.\" .Sq \&Va
-.\" as function arguments are variables.
-.\" .It
-.\" .Sq \&Ft
-.\" should be
-.\" .Sq \&Vt
-.\" as function return types are still types. Furthermore, the
-.\" .Sq \&Ft
-.\" should be removed and
-.\" .Sq \&Fo ,
-.\" which ostensibly follows it, should follow the same convention as
-.\" .Sq \&Va .
-.\" .It
-.\" .Sq \&Va
-.\" should formalise that only one or two arguments are acceptable: a
-.\" variable name and optional, preceding type.
-.\" .It
-.\" .Sq \&Fd
-.\" is ambiguous. It's commonly used to indicate an include file in the
-.\" synopsis section.
-.\" .Sq \&In
-.\" should be used, instead.
-.\" .It
-.\" Only the
-.\" .Sq \-literal
-.\" argument to
-.\" .Sq \&Bd
-.\" makes sense. The remaining ones should be removed.
-.\" .It
-.\" The
-.\" .Sq \&Xo
-.\" and
-.\" .Sq \&Xc
-.\" macros should be deprecated.
-.\" .It
-.\" The
-.\" .Sq \&Dt
-.\" macro lacks clarity. It should be absolutely clear which title will
-.\" render when formatting the manual page.
-.\" .It
-.\" A
-.\" .Sq \&Lx
-.\" should be provided for Linux (\(`a la
-.\" .Sq \&Ox ,
-.\" .Sq \&Nx
-.\" etc.).
-.\" .It
-.\" There's no way to refer to references in
-.\" .Sq \&Rs/Re
-.\" blocks.
-.\" .It
-.\" The \-split and \-nosplit dictates via
-.\" .Sq \&An
-.\" are re-set when entering and leaving the AUTHORS section.
-.\" .El
-.\" .
+.An Kristaps Dzonsons ,
+.Mt kristaps@bsd.lv .
git.ckatri.com / mandoc.git / blobdiff