Ubuntu Manpage: groff_man - GNU roff macro package for formatting man pages

name
synopsis
description
options
files
notes
authors
see also

NAME

       groff_man - GNU roff macro package for formatting man pages

SYNOPSIS

       groff -man [option ...] [input-file ...]
       groff -m man [option ...] [input-file ...]

DESCRIPTION

The man macro package for groff is used to produce manual pages (“man pages”) like the one you are
reading. GNU roff's implementation was written by James Clark.

This document presents the macros thematically to aid learners; for those needing only a quick reference,
the following table lists them alphabetically, with cross-references to appropriate subsections below.

Macro Meaning Subsection
───────────────────────────────────────────────────────────────────
.B Bold Font style macros
.BI Bold, italic alternating Font style macros
.BR Bold, roman alternating Font style macros
.EE Example end Document structure macros
.EX Example begin Document structure macros
.I Italic Font style macros
.IB Italic, bold alternating Font style macros
.IP Indented paragraph Paragraph macros
.IR Italic, roman alternating Font style macros
.LP (Left) paragraph Paragraph macros
.ME Mail-to end Hyperlink and email macros
.MT Mail-to start Hyperlink and email macros
.OP (Command-line) option Command synopsis macros
.P Paragraph Paragraph macros
.PP Paragraph Paragraph macros
.RB Roman, bold alternating Font style macros
.RE Relative-indent end Document structure macros
.RI Roman, italic alternating Font style macros
.RS Relative-indent start Document structure macros
.SB Small bold Font style macros
.SH Section heading Document structure macros
.SM Small Font style macros
.SS Subection heading Document structure macros
.SY Synopsis start Command synopsis macros
.TH Title heading Document structure macros
.TP Tagged paragraph Paragraph macros
.TQ Tagged paragraph continuation Paragraph macros
.UE URL end Hyperlink and email macros
.UR URL start Hyperlink and email macros
.YS Synopsis end Command synopsis macros

Macros whose use we discourage (.AT, .BT, .DT, .HP, .PD, .PT, and .UC) are described in subsection
“Deprecated features”, below.

Macro reference preliminaries
Each macro is described in a tagged paragraph. Closely related macros, such as .EX and .EE, are grouped
together.

Optional macro arguments are indicated by surrounding them with square brackets. If a macro accepts
multiple arguments, arguments containing whitespace must be double-quoted ("one two"), to be interpreted
correctly. Most macro arguments are strings that will be output as text; exceptions are noted.

Bear in mind that groff is fundamentally a programming system for typesetting. Consequently, the verb
“to set” is frequently used below in the sense “to typeset”.

Document structure macros
The highest level of organization of a man page is determined by this group of macros. .TH (title
heading) identifies the document as a man page and defines information enabling its indexing by mandb(8)
or a similar tool. Sections (.SH), one of which is mandatory and many of which are standardized,
facilitate quick location of relevant material by the reader and aid the man page writer to discuss all
essential aspects of the topic. Subsections (.SS) are optional and permit sections that grow long to
develop in a controlled way. Many technical discussions require examples; lengthy ones, especially those
reflecting multiple lines of input to or output from the system, are usefully bracketed by .EX and .EE.
When none of the foregoing meets a structural demand, a section of the discussion can be manually
indented within .RS and .RE macros.

.TH title section [footer-middle] [footer-outside] [header-middle]
Define the title of the man page as title and the section as section. See man(1) for details on
the section numbers and suffixes applicable to your system. title and section are positioned
together at the left and right in the header line (with section in parentheses immediately
appended to title). footer-middle is centered in the footer line. footer-outside is positioned
at the left in the footer line (or at the left on even pages and at the right on odd pages if
double-sided printing is active). header-middle is centered in the header line. If section is a
simple integer between 1 and 9 (inclusive), or is exactly “3p”, there is no need to specify
header-middle; the macro package will supply text for it.

For HTML output, headers and footers are completely suppressed.

Additionally, this macro starts a new page; the page number is reset to 1 (unless the -rC1 option
is given on the command line). This feature is intended only for formatting multiple man pages.

A man page should contain exactly one .TH call at or near the beginning of the file, prior to any
other macro calls.

By convention, footer-middle is the most recent modification date of the man page source document,
and footer-outside is the name and version or release of the project providing it.

.SH [heading-text]
Set heading-text as a section heading flush left. The text following .SH up to the end of the
line, or the text on the next input line if .SH is given no arguments, is set in bold (or the font
specified by the string register HF) slightly larger than the base font size. Additionally, the
left margin and indentation affecting subsequent text are reset to their default values. Text on
input lines after heading-text is set as a normal paragraph (.PP).

The content of heading-text and ordering of sections has been standardized by common practice, as
has much of the layout of material within sections. For example, a section called “Name” or
“NAME” must exist, must be the first section after the .TH call, and must contain only a line of
the form
page-topic[, ...] \- summary-description
for a man page to be properly indexed. See man(7) for the conventions prevailing on your system.

.SS [subheading-text]
Set subheading-text as a subsection heading indented (by default) partway between a section
heading and a normally-indented paragraph (.PP). The text following .SS up to the end of the
line, or the text on the next input line if .SS is given no arguments, is set in bold (or the font
specified by the string register HF) at the base font size. Additionally, the left margin and
indentation affecting subsequent text are reset to their default values. Text on input lines
after subheading-text is set as a normal paragraph (.PP).

.EX
.EE Begin and end example. After .EX, filling and hyphenation are disabled and a constant-width
(monospaced) font is selected. Calling .EE enables filling and restores the previous hyphenation
setting and font.

Example regions are useful for formatting code, shell sessions, and text file contents.

These macros are defined on many (but not all) legacy Unix systems running classic troff. To be
certain your page will be portable to those systems, copy their definitions from the an-ext.tmac
file of a groff installation.

.RS [indent]
Move the left margin to the right by the value indent, if specified, and by a default amount
otherwise; see subsection “Horizontal and vertical spacing” below. Calls to .RS can be nested;
each call increments by 1 the indentation level used by .RE. The indentation level prior to any
.RS calls is 1.

.RE [level]
Move the left margin back to that corresponding to indentation level level. If no argument is
given, move the left margin one level back.

Paragraph macros
A typical paragraph (.PP) is set at the current left margin, which by default is indented from the left
margin of the output device. In man pages and other technical literature, definition lists are
frequently encountered; these can be set as “tagged paragraphs” (.TP and .TQ), which have one or more
leading tags followed by a paragraph that has an additional left indent. The indented paragraph (.IP)
macro is useful to continue the indented content of a narrative started with .TP, or to present an
itemized or ordered list.

.LP
.PP
.P Begin a new paragraph; these macros are synonymous. They break the output line at the current
position, followed by a vertical space downward by a default amount (which can be changed by the
deprecated .PD macro). The font size and style are reset to defaults; see subsection “Font style
macros” below. Finally, the left margin and indentation are reset to default values.

.TP [indent]
Set a tagged, indented paragraph. The input line following this macro, known as the tag, is
printed at the current left margin. Subsequent text is indented by indent, if specified, and by a
default amount otherwise; see subsection “Horizontal and vertical spacing” below.

If the tag is not as wide as the indentation, the paragraph starts on the same line as the tag, at
the applicable indentation, and continues on the following lines. Otherwise, the descriptive part
of the paragraph begins on the line following the tag, entirely indented. The line containing the
tag can include a macro call, for instance to set the tag in bold with .B.

.TP was used to write the first paragraph of this description of .TP, and .IP the subsequent ones.

.TQ Set an additional tag for a paragraph tagged with .TP. The pending output line is broken. The
tag on the input line following this macro and subsequent lines are handled as with .TP.

This macro is not defined on legacy Unix systems running classic troff. To be certain your page
will be portable to those systems, copy its definition from the an-ext.tmac file of a groff
installation.

The descriptions of .LP, .PP, and .P above were written using .TP and .TQ.

.IP [tag] [indent]
Set an indented paragraph with an optional tag. The tag and indent arguments, if present, are
handled as with .TP, with the exception that the tag argument to .IP cannot include a macro call.

Two convenient use cases for .IP are

(1) to start a new paragraph with the same indentation as the previous .IP or .TP
paragraph, if no indent argument is given; and

(2) to set a paragraph with a short tag that is not semantically important, such as a
bullet (•)—obtained with the ‘\(bu’ character escape—or list enumerator, as seen in
this very paragraph.

Command synopsis macros
Command synopses are a staple of section 1 and 8 man pages. These macros aid you to construct one that
has the classical Unix appearance. Furthermore, some tools are able to interpret these macros
semantically and treat them appropriately for localization and/or presentation. A command synopsis is
wrapped in .SY/.YS calls, with command-line options of some formats indicated by .OP.

These macros are not defined on legacy Unix systems running classic troff. To be certain your page will
be portable to those systems, copy their definitions from the an-ext.tmac file of a groff installation.

.SY command
Begin synopsis. Hyphenation is turned off. The command argument is set in bold. The output line
is filled as normal, but if a break is required, subsequent output lines are indented by the width
of command plus a space.

.OP option-name [option-argument]
Indicate an optional command parameter called option-name, which is set in bold. If the option
takes an argument, specify option-argument using a noun, abbreviation, or hyphenated noun phrase.
If present, option-argument is preceded by a space and set in italics. Square brackets (in roman)
surround both arguments.

.YS End synopsis. Restore indentation and hyphenation to previous values.

Multiple .SY/.YS blocks can be specified, for instance to distinguish differing modes of operation of a
complex command like tar(1); each will be separated by a paragraph space.

.SY can also be repeated multiple times before a closing .YS, which is useful to indicate synonymous ways
of invoking a particular mode of operation.

For example,

.SY groff
.OP \-abcegiklpstzCEGNRSUVXZ
.OP \-d cs
.OP \-f fam
.OP \-F dir
.OP \-I dir
.OP \-K arg
.OP \-L arg
.OP \-m name
.OP \-M dir
.OP \-n num
.OP \-o list
.OP \-P arg
.OP \-r cn
.OP \-T dev
.OP \-w name
.OP \-W name
.RI [ file
\&.\|.\|.\&]
.YS
.
.SY groff
.B \-h
.SY groff
.B \-\-help
.YS

produces the following output.

groff [-abcegiklpstzCEGNRSUVXZ] [-d cs] [-f fam] [-F dir] [-I dir] [-K arg] [-L arg] [-m name]
[-M dir] [-n num] [-o list] [-P arg] [-r cn] [-T dev] [-w name] [-W name] [file ...]

groff -h
groff --help

Several features of the above example are of note.

• The empty request (.), which does nothing, is used for vertical spacing in the input file for
readability by the document maintainer. Do not put empty lines in a roff source document.

• The command and option names are presented in bold to cue the user that they should be input
literally.

• Option dashes are specified with the ‘\-’ escape sequence; this is an important practice to make
them clearly visible and to facilitate cut-and-paste from the rendered man page to a shell prompt
or text file.

• Option arguments and command operands are presented in italics (underlined on some output devices,
such as terminals and emulators), to cue the user that they must be replaced with appropriate
text.

• Symbols that are neither to be typed literally nor simply replaced appear in the roman style;
brackets surround optional arguments, and an ellipsis indicates that the previous syntactical
element may be repeated arbitrarily.

Some man pages use a brace-and-pipe notation such as “{--diff|--compare}” to indicate that one and
only one of the ‘|’-separated items within the braces must be input. If this braced construct is
furthermore surrounded by square brackets, it means that at most one of the items is accepted.

Authors of man pages should note the use of the zero-width space escape sequence ‘\&’ on both
sides of the ellipsis; this is a good practice to avoid surprises in the event the ellipsis gets
refilled in your text editor. See “Portability”, below. The morbidly curious may consult
groff(7) regarding the narrow-space escape sequence ‘\|’.

Hyperlink and email macros
Email addresses are bracketed with .MT/.ME and URL hyperlinks with .UR/.UE.

.MT address
.ME [punctuation]
Identify address as an RFC 6068 addr-spec for a “mailto:” URI with the text between the two macro
calls as the link text. A punctuation argument to .ME is placed at the end of the link text
without intervening space. Note that address may not be visible in the output text, particularly
if the man page is being viewed as HTML. On a device that is not a browser, address is set in
angle brackets after the link text and before punctuation.

When rendered by groff to a TTY or PostScript output device,

Contact
.MT fred.foonly@\:fubar.net
Fred Foonly
.ME
for more information.

displays as: “Contact Fred Foonly ⟨fred.foonly@fubar.net⟩ for more information.”.

The use of ‘\:’ to insert hyphenless discretionary breaks is a groff extension and can be omitted.

.UR URL
.UE [punctuation]
Identify URL as an RFC 3986 URI hyperlink with the text between the two macro calls as the link
text. A punctuation argument to .UE is placed at the end of the link text without intervening
space. Note that URL may not be visible in the output text, particularly if the man page is being
viewed as HTML. On a device that is not a browser, URL is set in angle brackets after the link
text and before punctuation.

When rendered by groff to a TTY or PostScript output device,

The GNU Project of the Free Software Foundation hosts the
.UR https://\:www.gnu.org/\:software/\:groff/
Groff home page
.UE .

displays as: “The GNU Project of the Free Software Foundation hosts the Groff home page ⟨https://
www.gnu.org/software/groff/⟩.”.

The use of ‘\:’ to insert hyphenless discretionary breaks is a groff extension and can be omitted.

Font style macros
The man macro package is limited in its font styling options, offering only bold (.B), italic (.I), and
roman (the default). Italic text is usually set underscored instead on terminals and other classical
nroff-style output devices. The .SM and .SB macros set text in roman or bold, respectively, at a smaller
point size; these differ visually from regular-sized roman or bold text only on troff-style output
devices. The foregoing macros cause word breaks before and after their arguments, but it is often
necessary to set text in different styles without intervening whitespace. The macros .BI, .BR, .IB, .IR,
.RB, and .RI, where ‘B’, ‘I’, and ‘R’ indicate bold, italic, and roman, respectively, set their odd- and
even-numbered arguments in alternating styles, with no whitespace separating them.

Because font styles are presentational rather than semantic, conflicting traditions have arisen regarding
which font styles should be used to mark file or path names, environment variables, in-line literals, and
even man page cross-references.

The default font size and family (for troff output devices) is 10-point Times. The default style is
roman.

.B [text]
Set text in bold. If the macro is given no arguments, the text of the next input line is set in
bold.

Use bold for literal portions of syntax synopses, for command-line options in running text, and
for literals that are major topics of the subject under discussion; for example, this page uses
bold for macro and register names. In .EX/.EE examples of interactive I/O (such as a shell
session), set only the user-typed input in bold.

.I [text]
Set text in italics. If the macro is given no arguments, the text of the next input line is set
in italics.

Use italics for file and path names, for environment variables, for enumeration or preprocessor
constants in C, for variable (user-determined) portions of syntax synopses, for the first
occurrence only of a technical concept being introduced, for names of works of software (including
commands and functions, but excluding names of operating systems or their kernels), and anywhere a
parameter requiring replacement by the user is encountered. An exception involves variable text
in a context that is already marked up in italics, such as file or path names with variable
components; in such cases, follow the convention of mathematical typography: set the file or path
name in italics as usual (see .IR below), but use roman for the variable part, and italics again
in running roman text when referring to the variable material.

.SM [text]
Set text one point size smaller than the default size. If the macro is given no arguments, the
text of the next input line is set smaller.

Note: nroff-style output devices, such as terminals, will render text at the normal font size
instead. Do not rely upon .SM to communicate semantic information distinct from using roman style
at the normal size; it will be hidden from readers using such devices.

.SB [text]
Set text in bold, one point size smaller than the default size. If the macro is given no
arguments, the text of the next input line is set smaller and in bold.

Note: nroff-style output devices, such as terminals, will render text in bold at the normal font
size instead. Do not rely upon .SB to communicate semantic information distinct from using bold
style at the normal size; it will be hidden from readers using such devices.

Note what is not prescribed for setting in bold or italics above: elements of “synopsis language” such as
ellipses and brackets around options; proper names and adjectives; titles of anything other than works of
literature or software; identifiers for standards documents or technical reports such as CSTR #54,
RFC 1918, Unicode 11.0, or POSIX.1-2017; acronyms; and occurrences after the first of a technical term or
piece of jargon. Again, the names of operating systems and their kernels are, by practically universal
convention, set in roman.

Be frugal with the use of italics for emphasis, and particularly with the use of bold. Brief runs of
literal text, such as references to individual characters or short strings, including section and
subsection headings of man pages, are suitable objects for quotation; see the ‘\(lq’, ‘\(rq’, ‘\(oq’, and
‘\(cq’ escapes in subsection “Portability” below.

Unlike the above font style macros, the font alternation macros below accept only arguments on the same
line as the macro call. If whitespace is required within one of the arguments, first consider whether
the same result could be achieved with as much clarity by using the single-style macros on separate input
lines. When it cannot, double-quote an argument with one or more embedded space characters. Setting all
three different styles within one whitespace-delimited word presents challenges; it is possible with the
‘\c’ and/or ‘\f’ escapes, but see subsection “Portability” below for caveats.

.BI bold-text italic-text ...
Set each argument in bold and italics, alternately.

.BI \-r name = n

.BR bold-text roman-text ...
Set each argument in bold and roman, alternately.

Any such change becomes effective with the first use of
.BR .NH ,
.I after
the new alias is defined.

.IB italic-text bold-text ...
Set each argument in italics and bold, alternately.

All macro package files must be named
.IB name .tmac
to fully use the
.I tmac
mechanism.

.IR italic-text roman-text ...
Set each argument in italics and roman, alternately.

This is the first command of the
.IR prologue .

.RB roman-text bold-text ...
Set each argument in roman and bold, alternately.

Also, the statement
.RB \(oq "delim on" \(cq
is not handled specially.

.RI roman-text italic-text ...
Set each argument in roman and italics, alternately.

.RI [ file
\&.\|.\|.\&]

Horizontal and vertical spacing
The indent argument accepted by .RS, .IP, .TP, and the deprecated .HP is a number plus an optional
scaling indicator. If no scaling indicator is given, the man package assumes ‘n’; that is, the width of
a letter “n” in the font current when the macro is called. See section “Numerical Expressions” in
groff(7) for further details. An indent specified in a call to .IP, .TP, or the deprecated .HP persists
until (1) another of these macros is called with an explicit indent argument, or (2) .SH, .SS, or .PP or
its synonyms is called; these clear the indent entirely.

Indents set by .RS move the left margin and persist until .RS, .RE, .SH, or .SS is called. The default
indentation, exhibited by ordinary .PP paragraphs not within an .RS/.RE relative indent, is 7.2n in troff
mode and 7n in nroff mode. The HTML output device is an exception; it ignores indentation completely.
This same indentation is used again (additively) for the defaults of .IP, .TP, .RS, and the deprecated
.HP. Section headings (.SH) are set flush with the left margin of the output device, and subsection
headings (.SS) are indented 3n.

Resist the temptation to mock up tabular or multi-column output with ASCII tab characters or the
indentation arguments to .IP, .TP, .RS, or the deprecated .HP; the result may not render comprehensibly
on an output device you fail to check, or which is developed in the future. The table preprocessor
tbl(1) can likely meet your needs.

The following macros cause a line break with the insertion of vertical space: .SH, .SS, .TP, .TQ, .PP
(and its synonyms), .IP, and the deprecated .HP. The default inter-section and inter-paragraph spacing
is 1 line in nroff mode, and 0.4v in troff mode. (The deprecated macro .PD can change this vertical
spacing, but its use is discouraged.) The macros .RS, .RE, .EX, and .EE also cause a break but no
insertion of vertical space.

Number registers
Number registers are described in section “Options” below.

String registers
The following strings are defined.

\*R expands to the character escape for the “registered sign” glyph, ‘\(rg’, if available, and
“(Reg.)” otherwise.

\*S expands to an escape setting the font size to the document default.

\*(HF expands to the font identifier used to print headings and subheadings. The default is ‘B’.

\*(lq
\*(rq expand to the character escapes for left and right double-quotation marks, ‘\(lq’ and ‘\(rq’,
respectively.

\*(Tm expands to the character escape for the “trade mark sign” glyph, ‘\(tm’, if available, and “(TM)”
otherwise.

Interaction with preprocessors
When a preprocessor like tbl or eqn is needed, a hint can be given to the man page formatter by making
the first line of a man page look like this:

'\" word

Note that the line starts with an apostrophe ('), not a dot, and that a single space character follows
the double quote. The word consists of one letter for each needed preprocessor: ‘e’ for eqn, ‘r’ for
refer, and ‘t’ for tbl. Modern implementations of the man program interpret this first line and
automatically call the right preprocessor(s).

The usual tbl and eqn macros for table and equation inclusion, .TS, .T&, .TE, .EQ, and .EN, may be used
freely. Note that nroff output devices are extremely limited in presentation of mathematical equations.

Portability
The two major syntactical categories of roff languages are requests and escapes. Since the man macros
are implemented in terms of groff requests and escapes, one can, in principle, supplement the
functionality of man with these lower-level elements where necessary.

Note, however, that using raw groff requests is likely to make your page render poorly on the class of
viewers that transform it to HTML. Some requests make implicit assumptions about things like character
and page sizes that may not hold in an HTML environment; also, many of these viewers don't interpret the
full groff vocabulary, a problem that can lead to portions of your text being silently dropped.

For portability to modern viewers, it is best to write your page entirely with the macros described in
this page (except for the ones identified as deprecated, which should be avoided). The macros we have
described as extensions (.EX/.EE, .SY/.OP/.YS, .UR/.UE, and .MT/.ME) should be used with caution, as they
may not yet be built in to some viewer that is important to your audience. If in doubt, copy the
implementation into your page—after the .TH call and the “Name” section, to accommodate timid mandb
implementations.

Similar caveats apply to escapes. Some escape sequences are however required for correct typesetting
even in man pages and usually do not cause portability problems:

\" Comment. Everything after the double-quote to the end of the input line is ignored. Whole-line
comments are frequently placed immediately after the empty request ‘.’.

\newline
Join the next input line to the current one. Except for the update of the input line counter
(used for diagnostic messages and related purposes), a series of lines ending in backslash-newline
is transparent to groff. Use this escape to break excessively input long lines for document
maintenance.

\~ Adjustable, non-breaking space character. Use this escape to prevent a break inside a short
phrase or between a numerical quantity and its corresponding unit(s).

Before starting the motor, set the output speed to\~1.
There are 1,024\~bytes in 1\~kiB.
CSTR\~#8 documents the B language.

\& Zero-width space. Append to an input line to prevent an end-of-sentence punctuation sequence from
being recognized as such, or insert at the beginning of an input line to prevent a dot or
apostrophe from being interpreted as the beginning of a roff request.

\(aq ASCII apostrophe. Use for syntax elements of programming languages because some output devices
might replace unescaped apostrophes with right single quotation marks.

\(oq Opening single quotation mark.
\(cq Closing single quotation mark.

Use these for paired directional single quotes, ‘like this’.

\(dq ASCII double-quote. Sometimes needed after macro calls to prevent the interpretation of the ASCII
quotation mark character ‘"’ as the beginning or end of a macro argument.

\(lq Left double quotation mark.
\(rq Right double quotation mark.

Use these for paired directional double quotes, “like this”.

\(em Em-dash. Use for an interruption in a sentence—such as this one.

\(en En-dash. Use to separate the two ends of a range, in particular between numbers, for example: the
digits 1–9.

\(ga ASCII grave accent. Use for syntax elements of programming languages, for example shell command
substitutions, because some output devices might replace unescaped grave accents with left single
quotation marks.

\(ha ASCII circumflex accent. Use for syntax elements of programming languages because some output
devices might replace unescaped circumflex accents with non-ASCII glyphs like the Unicode U+02C6
modifier letter circumflex.

\(ti ASCII tilde. Use for syntax elements of programming languages because some output devices might
replace unescaped tildes with non-ASCII glyphs like the Unicode U+02DC small tilde.

\- Minus sign. Also use this to display syntax elements that require the ASCII hyphen-minus
character, for example command-line options and C language operators. The unescaped ‘-’ input
character is not appropriate for these cases because it may render as a hyphen on some output
devices.

\c If this escape sequence occurs at the end of an input line, no white space is inserted between the
last glyph on it and the first glyph resulting from the next input line. This is occasionally
useful when three different fonts are needed in a single word.

Normally, the final output file should be named
.IB file .pdf\c
\&.

Note that when using this trick with the .BI or .RI macros, you will need to manually add an
italic correction escape ‘\/’ before the ‘\c’ due to way macros expand their arguments.

Files processed with
.B groff \-mom
(or
.BI "\-m " mom\/\c
) produce PostScript output by default.

Alternatively, and perhaps with better portability, the ‘\f’ font escape sequence can be used; see
below. Using ‘\c’ to include the output from more than one input line into the next-line argument
of a .TP macro will render incorrectly with groff 1.22.3, mandoc 1.14.1, older versions of these
programs, and perhaps with some other formatters.

\e Widely used in man pages to represent a backslash output glyph. It works reliably as long as the
.ec request is not used, which should never happen in man pages, and it is slightly more portable
than the more exact ‘\(rs’ (“reverse solidus”) escape sequence.

\fB, \fI, \fR, \fP
Switch to bold, italic, roman, or back to the previous font, respectively. Either these or ‘\c’
is needed when three different fonts are required in a single whitespace-delimited word.

.RB [ \-\-reference\-dictionary=\fI\,name\/\fP ]

.RB [ \-\-reference\-dictionary=\c
.IR name ]

Font escapes may be more portable than ‘\c’. As shown above, it is up to you to account for
italic corrections with ‘\/’ and ‘\,’, which are themselves groff extensions, if desired and if
supported by your implementation.

Note that ‘\fP’ reliably returns to the style in use immediately preceding the previous ‘\f’
escape only if no sectioning, paragraph, or font face macro calls have intervened.

As long as only two fonts are needed in any single whitespace-delimited word, font alternation
macros like .BI usually result in more readable source code than ‘\f’ escapes do.

For maximum portability, escape sequences and special characters not listed above are better avoided in
man pages.

Deprecated features
Use of the following is discouraged.

.AT [system [release]]
Alter the footer for use with AT&T man pages, overriding any definition of the footer-outside
argument to .TH. This macro exists only for compatibility; don't use it.

The first argument system can be:

3 7th edition (default)

4 System III

5 System V

The optional second argument release specifies the release number, such as in “System V Release
3”.

.BT Set the page footer. Redefine this macro to get control of the footer.

.DT Set tabs every 0.5 inches. Since this macro is always called during a .TH macro, it makes sense
to call it only if the tab positions have been changed.

Use of this presentation-level macro is deprecated. It translates poorly to HTML, under which
exact whitespace control and tabbing are not readily available. Thus, information or distinctions
that you use .DT to express are likely to be lost. If you feel tempted to use it, you should
probably be composing a table using tbl(1) markup instead.

.HP [indent]
Set up a paragraph with a hanging left indentation. The indent argument, if present, is handled
as with .TP.

Use of this presentation-level macro is deprecated. While it is universally portable to legacy
Unix systems, a hanging indentation cannot be expressed naturally under HTML, and many HTML-based
manual viewers simply interpret it as a starter for a normal paragraph. Thus, any information or
distinction you tried to express with the indentation may be lost.

.PD [vertical-space]
Define the vertical space between paragraphs or (sub)sections. The optional argument vertical-
space specifies the amount of space; the default scaling is ‘v’). Without an argument, the
spacing is reset to its default value; see “Horizontal and vertical spacing” above.

Use of this presentation-level macro is deprecated. It translates poorly to HTML, under which
exact control of inter-paragraph spacing is not readily available. Thus, information or
distinctions that you use .PD to express are likely to be lost.

.PT Set the page header. Redefine this macro to get control of the header.

.UC [version]
Alter the footer for use with BSD man pages, overriding any definition of the footer-outside
argument to .TH. This macro exists only for compatibility; don't use it.

The argument version can be:

3 3rd Berkeley Distribution (default)

4 4th Berkeley Distribution

5 4.2 Berkeley Distribution

6 4.3 Berkeley Distribution

7 4.4 Berkeley Distribution

History
According to its own man(7) page, Version 7 Unix (1979) supported all of the macros described in this
page not listed as GNU extensions, except .P, .SB, .SS, and the deprecated .AT, .BT, .PT, and .UC. The
only string registers defined were R and S; no number registers were documented.

OPTIONS

The following groff options set number registers recognized and used by the man macro package.

-rcR=1 Continuous rendering. Create a single, very long page instead of multiple pages. This is the
default in nroff mode. Use -rcR=0 to disable it.

-rC1 Number pages continuously. If more than one man page is given on the command line, number the
pages continuously, rather than starting each at 1.

-rD1 Enable double-sided printing. Footers for even and odd pages are formatted differently; see the
description of .TH in “Document structure macros”, above.

-rFT=footer-distance
Set distance of the footer, relative to the bottom of the page if negative or relative to the top
if positive, to footer-distance. The default is -0.5i.

-rHY=flags
Set hyphenation flags. Permissible values of flags are documented in section “Hyphenation” of
groff(7). The default is 4 if continuous rendering is enabled (-rcR=1 above), and 6 otherwise.

-rIN=indent
Set the body text indentation (for normal paragraphs) to indent. See “Horizontal and vertical
spacing” above for the default indentation value. For nroff, indent should always be an integer
multiple of unit ‘n’ to get consistent indentation.

-rLL=line-length
Set line length. If this option is not given, the line length is set to respect any value set by
a prior “.ll” request (which must be in effect when the .TH macro is invoked), if this differs
from the built-in default for the formatter; otherwise it defaults to 78n in nroff mode and 6.5i
in troff mode.

Note that the use of a “.ll” request to initialize the line length is supported for backward
compatibility with some versions of the man program; direct initialization of the LL register
should always be preferred to the use of such a request. In particular, note that a “.ll 65n”
request does not preserve the normal nroff default line length (the man default initialization to
78n prevails), whereas the -rLL=65n option, or an equivalent “.nr LL 65n” request preceding the
use of the .TH macro, does set a line length of 65n.

-rLT=title-length
Set title length. If this option is not given, the title length defaults to the line length.

-rPn Start enumeration of pages at n rather than 1.

-rSpoint-size
Use point-size as the base document font size. Acceptable values are 10, 11, or 12. See
subsection “Font style macros” above for the default.

-rSN=subsection-indent
Set subsection indentation to subsection-indent. See “Horizontal and vertical spacing” above for
the default indentation value.

-rXp After page p, number pages as pa, pb, pc, and so forth. For example, the option -rX2 produces the
following page numbers: 1, 2, 2a, 2b, 2c, and so on.

FILES

       /usr/share/groff/1.22.4/tmac/man.tmac
       /usr/share/groff/1.22.4/tmac/an.tmac
              These are wrapper files to call andoc.tmac.

       /usr/share/groff/1.22.4/tmac/andoc.tmac
              This brief groff program detects whether the man or mdoc macro package is being used by a document
              and  loads  the correct macro definitions, taking advantage of the fact that pages using them must
              call .TH or .Dd, respectively, as their first macro.  Because the wrappers above load this file, a
              man program or user typing, for example, “groff -man page.1”, need not know which package the file
              page.1 uses.  Multiple man pages, in either format, can be handled.

       /usr/share/groff/1.22.4/tmac/an-old.tmac
              Most man macros are contained in this file.  It also loads the  GNU  extensions  from  an-ext.tmac
              (see below).

       /usr/share/groff/1.22.4/tmac/an-ext.tmac
              The  extension  macro  definitions  for  .SY,  .OP,  .YS,  .TQ,  .EX/.EE, .UR/.UE, and .MT/.ME are
              contained in  this  file,  which  is  written  in  classic  troff  and  permissively  licensed—not
              copylefted.  Man page authors concerned about portability to legacy Unix systems are encouraged to
              copy these definitions into their pages, and maintainers of troff  implementations  or  work-alike
              systems that format man pages are encouraged to re-use them.

              Note  that  the  definitions for these macros are read after the call of .TH, so they will replace
              any macros of the same names preceding it in your file.  If you use your  own  implementations  of
              these macros, they must be defined after calling .TH to have any effect.

       /usr/share/groff/site-tmac/man.local
              Local changes and customizations should be put into this file.

NOTES

Some tips on troubleshooting your man pages follow.

• .RS doesn't indent relative to my indented paragraph
The .RS macro sets the indentation relative to the amount of a normal paragraph (.PP and its
synonyms). The same default indentation amount is used for .RS, .IP, .TP, and the deprecated .HP.
If you need to start an indent relative to an indented paragraph, call .RS repeatedly until an
acceptable indentation is achieved, or give .RS an indentation argument that is at least as much
as the paragraph's indentation amount relative to an adjacent .PP paragraph. See “Horizontal and
vertical spacing” above for the values.

• .RE doesn't reset the indent to the expected level
• warning: scale indicator invalid in this context
• warning: number register 'an-saved-marginn' not defined
• warning: number register 'an-saved-prevailing-indentn' not defined
The .RS macro takes an indentation amount as an argument; the .RE macro's argument is a specific
indentation level. .RE 1 goes to the level before any .RS macros were called, .RE 2 goes to the
level of the first .RS call you made, and so forth. If you desire symmetry in your macro calls,
simply issue one .RE without an argument for each .RS that precedes it.

After calls to the .SH and .SS sectioning macros, all relative indents are cleared and calls to
.RE have no effect.

AUTHORS

       The GNU version of the man macro package was written by James  Clark  and  contributors.   The  extension
       macros were written by Werner Lemberg ⟨wl@gnu.org⟩ and Eric S. Raymond ⟨esr@thyrsus.com⟩.

       This  document  was  originally  written  for  the  Debian  GNU/Linux  system by Susan G. Kleinmann ⟨sgk@
       debian.org⟩.  It was corrected and updated by Werner Lemberg and  G.  Branden  Robinson.   The  extension
       macros  were  documented  by  Eric  S. Raymond; he also originated the portability section, to which Ingo
       Schwarze contributed most of the material on escape sequences.