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groff_man_style(7) Miscellaneous Information Manual groff_man_style(7)
groff_man_style - GNU roff man page tutorial and style guide
groff -man [option ...] [file ...]
groff -m man [option ...] [file ...]
The GNU implementation of the man macro package is part of the
groff document formatting system. It is used to compose manual
pages (“man pages”) like the one you are reading. This document
presents the macros thematically; for those needing only a quick
reference, the following table lists them alphabetically, with
references to appropriate subsections below. Experienced man
authors may prefer groff_man(7).
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
.HP Begin paragraph with hanging indent Paragraphing macros
.I Italic Font style macros
.IB Italic, bold alternating Font style macros
.IP Indented paragraph Paragraphing macros
.IR Italic, roman alternating Font style macros
.LP Begin paragraph Paragraphing macros
.ME Mail-to end Hyperlink macros
.MR Man page cross reference Hyperlink macros
.MT Mail-to start Hyperlink macros
.P Begin paragraph Paragraphing macros
.PP Begin paragraph Paragraphing macros
.RB Roman, bold alternating Font style macros
.RE Relative inset end Document structure macros
.RI Roman, italic alternating Font style macros
.RS Relative inset start Document structure macros
.SH Section heading Document structure macros
.SM Small Font style macros
.SS Subsection heading Document structure macros
.SY Synopsis start Synopsis macros
.TH Title heading Document structure macros
.TP Tagged paragraph Paragraphing macros
.TQ Supplemental paragraph tag Paragraphing macros
.UE URI end Hyperlink macros
.UR URI start Hyperlink macros
.YS Synopsis end Synopsis macros
We discuss other macros (AT, DT, OP, PD, SB, and UC) in subsection
“Deprecated features” below.
Throughout Unix documentation, a manual entry is referred to
simply as a “man page”, regardless of its length, without gendered
implication, and irrespective of the macro package selected for
its composition.
A man page employs the Unix line-ending convention (U+000A only).
Some basic Latin characters have special meaning to roff; see
subsection “Portability” below.
Fundamental concepts
groff is a programming system for typesetting: we thus often use
the verb “to set” in the sense “to typeset”. The formatter
troff(1) collects words from the input and fills output lines with
as many as can fit. Words are separated by spaces and newlines.
A transition to a new output line is called a break. Breaks can
occur at explicit hyphens, at \% or \: escape sequences (see
subsection “Portability” below), or at predetermined locations in
a word if automatic hyphenation is enabled (see the -rHY option in
section “Options” below). An output line may be supplemented with
inter-sentence space, then potentially adjusted with more space to
a consistent length (see the -dAD option). roff(7) details these
processes. The formatter prepares output for terminals or for
more capable typesetters that can change the type size and font
family.
A roff document can contain control lines, which start with a dot
(.) or neutral apostrophe ('). All other input lines are text
lines to be formatted. A macro collects control and/or text lines
to ease document composition. man is a macro package. To call a
macro, put its name after a dot on a control line. Some macros
interpret arguments, words that follow its name. A newline,
unless escaped (see subsection “Portability” below), marks the end
of the macro call. A control line with no macro name on it is
called an empty request; it does nothing.
We describe below several man macros that plant one-line input
traps: the next input line that directly produces formatted output
is treated specially. For man documents that follow the advice in
section “Portability” below, this means that control lines using
the empty request and uncommented input lines ending with an
escaped newline do not spring the trap; anything else does (but
see the TP macro description).
Macro reference preliminaries
A tagged paragraph describes each macro. We present coupled pairs
together, as with EX and EE. Optional macro arguments are
indicated by surrounding them with square brackets. If a macro
accepts multiple arguments, those containing space characters must
be double-quoted to be interpreted correctly. If you require an
empty macro argument, specify it as a pair of neutral double
quotes (""). See section “Notes” below for examples of cases
where better alternatives to empty arguments in macro calls are
available. Most macro arguments are formatted as text in the
output; exceptions are noted. We identify some macros as
extensions to the set originally implemented. They are not
supported everywhere; see subsection “Use of extensions” below.
Document structure macros
Document structure macros organize a man page's content. All of
them break the output line. TH (title heading) identifies the
document as a man page and configures the page headers and
footers. Section headings (SH), one of which is mandatory and
many of which are conventionally expected, facilitate location of
material by the reader and aid the man page writer to discuss all
essential aspects of the topics presented. Subsection headings
(SS) are optional and permit sections that grow long to develop in
a controlled way. Many technical discussions benefit from
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,
use RS/RE to inset a region within a (sub)section.
.TH identifier section [footer-middle [footer-inside [header-
middle]]]
Populate the page header and footer. roff systems refer to
these collectively as “titles”. Together, identifier and
the section of the manual to which it belongs can uniquely
identify a man document on the system. This use of
“section” has nothing to do with the section headings
otherwise discussed in this page; it arises from the
organizational scheme of printed and bound Unix manuals.
See man(1) or intro(1) for the manual sectioning applicable
to your system. identifier and section are positioned at
the left and right in the header; the latter is set after
the former, in parentheses and without space. footer-
middle is centered in the footer. By default, footer-
inside is positioned at the bottom left. Use of the
double-sided layout option -rD1 places footer-inside at the
bottom left on recto (odd-numbered) pages, and the bottom
right on verso (even-numbered) pages. By default, the
outside footer is the page number. Use of the continuous-
rendering option -rcR=1 replaces it with identifier and
section, as in the header. header-middle is centered in
the header. If section is an integer between 1 and 9
(inclusive), there is no need to specify header-middle;
an.tmac supplies text for it. If identifier or footer-
inside would overrun the space available in the header
and/or footer, this package may abbreviate them with
ellipses (...). In HTML output, headers and footers are
suppressed.
Additionally, this macro breaks the page, resetting the
number to 1 (unless the -rC1 option is given). This
feature is intended only for formatting multiple man
documents in sequence.
A valid man document calls TH only once, early in the file,
prior to any other macro calls.
By convention, footer-middle is the date of the most recent
modification to the man page source document, and footer-
inside is the name and version or release of the project
providing it.
.SH [heading-text]
Set heading-text as a section heading. Given no argument,
SH plants a one-line input trap; text on the next line
becomes heading-text. The heading text is set in bold (or
the font specified by the string HF), and, on typesetters,
slightly larger than the base type size. If the heading
font \*[HF] is bold, use of an italic style in heading-text
is mapped to the bold-italic style if available in the font
family. The inset level is reset to 1; see subsection
“Horizontal and vertical spacing” below. Text lines after
the call are set as an ordinary paragraph (P).
The content of heading-text and ordering of sections
follows a set of common practices, as does 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 text of
the form
topic[, another-topic]... \- summary-description
for tools like makewhatis(8) or mandb(8) to index them.
.SS [subheading-text]
Set subheading-text as a subsection heading indented
between a section heading and an ordinary paragraph (P).
Given no argument, SS plants a one-line input trap; text on
the next line becomes subheading-text. The subheading text
is set in bold (or the font specified by the string HF).
If the heading font \*[HF] is bold, use of an italic style
in subheading-text is mapped to the bold-italic style if
available in the font family. The inset level is reset to
1; see subsection “Horizontal and vertical spacing” below.
Text lines after the call are set as an ordinary paragraph
(P).
.EX
.EE Begin and end example. After EX, filling is disabled (and,
on typesetters, a monospaced font family is selected).
Calling EE enables filling (and restores the previous
family).
Example regions are useful for formatting code, shell
sessions, and text file contents. An example region is not
a “literal mode” of any sort: special character escape
sequences must still be used to produce correct glyphs for
', -, \, ^, `, and ~ (see subsection “Portability” below).
Sentence endings are still detected and additional inter-
sentence space applied. If the amount of additional inter-
sentence spacing is altered, the rendering of, for
instance, regular expressions using . or ? followed by
multiple spaces can change. Use the dummy character escape
sequence \& before the spaces.
Ninth Edition Unix introduced the EX and EE extensions.
Documenter's Workbench (DWB), Heirloom Doctools, and Plan 9
troffs, and mandoc (since 1.12.2) support them. Solaris 10
troff does not.
.RS [inset-amount]
Start new relative inset. man saves any current inset
amount and moves right by: inset-amount, if specified; the
indentation amount of the preceding IP, TP, or HP macro
call if no (sub-)sectioning or ordinary paragraphing macro
has intervened; or the amount of the IN register. RS calls
can nest; each increments by 1 the level used by RE. The
level prior to any RS call is 1.
.RE [inset-level]
End a relative inset, restoring the inset amount of inset-
level, or 1 if none is specified.
Paragraphing macros
These macros break the output line. An ordinary paragraph (P)
like this one indents all output lines by the same amount. A
hanging paragraph (HP) is a cosmetic variant of P with a hanging
indent. Definition lists frequently occur in man pages; these can
be set as tagged paragraphs, which have one (TP) or more (TQ)
leading tags followed by a paragraph that has an additional
indentation. 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. If paragraph macro has
been called since SH or SS, all except for TQ follow the break
with vertical space (in an amount configured by the deprecated PD
macro); see subsection “Horizontal and vertical spacing” below.
Except for TQ, these macros reset the type size and font style to
defaults, and restore the configured hyphenation mode.
.P
.LP
.PP Begin a new paragraph; these macros are synonymous. Any
indentation from use of IP, TP, or HP is cleared. The
inset amount, as affected by RS and RE, is not.
.HP [indentation]
Set a paragraph with a hanging indentation. Text on output
lines after the first is indented by indentation, if
specified, and by the amount of the IN register otherwise.
Caution: A hanging indentation cannot be expressed
naturally in (pure) HTML, a hanging paragraph is not
distinguishable from an ordinary one if it formats on only
one output line, and non-roff-based man page interpreters
may treat HP as an ordinary paragraph anyway. Thus,
information or distinctions you mean to express with
indentation may be lost.
.TP [indentation]
Set an indented paragraph with a leading unindented tag.
The macro plants a one-line input trap that honors the \c
escape sequence; text on the next line becomes the tag, set
without indentation. Text on subsequent lines is indented
by indentation, if specified, and by the amount of the IN
register otherwise. If the tag, plus the “tag spacing”
stored in the TS register (see section “Options” below) is
wider than the indentation, the package breaks the line
after the tag.
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 one.
.TQ Set an additional tag for a paragraph tagged with TP,
planting a one-line input trap as with TP.
TQ is a GNU extension supported by Heirloom Doctools troff
(since Git snapshot 151220) and mandoc (since 1.14.5) but
not by DWB, Plan 9, or Solaris 10 troffs.
The description of P, LP, and PP above was written using TP
and TQ.
.IP [mark [indentation]]
Set an indented paragraph with an optional mark.
Arguments, if present, are handled as with TP, except that
the mark argument to IP cannot include a macro call, and
the tag separation amount stored in the TS register is not
enforced.
Two convenient uses for IP are
(1) to start a new paragraph with the same indentation
as an immediately preceding IP or TP paragraph, if
no indentation argument is given; and
(2) to set a paragraph with a short mark that is not
semantically important, such as a bullet
(•)—obtained with the \[bu] special character
escape sequence—or list enumerator, as seen in
this very paragraph.
Synopsis macros
Use SY and YS to summarize syntax using familiar Unix conventions.
Heirloom Doctools troff and mandoc (since 1.14.5) support these
GNU extensions; DWB, Plan 9, or Solaris 10 troffs do not.
.SY keyword [suffix]
Begin synopsis. Adjustment and automatic hyphenation are
disabled. If SY has already been called without a
corresponding YS, a break is performed. keyword and any
suffix are set in bold. When suffix is present, groff man
sets the next word after it without intervening space. If
a break is required in subsequent text (up to a
paragraphing, sectioning, or YS macro call), lines after
the first are indented. Unless the previous synopsis's
indentation is reused (see YS below), output lines after
the first indent by the width of the pending output line up
to the end of keyword plus a space, if keyword is the only
argument, and up to the end of suffix otherwise.
.YS [reuse-indentation]
End synopsis, breaking the line and restoring indentation,
adjustment, and hyphenation to their previous states. If
an argument is given, the indentation corresponding to the
previous SY call is reused by the next SY call instead of
being computed.
Interleave multiple SY/YS blocks with paragraphing macros to
distinguish differing modes of operation of a complex command like
tar(1). Omit the paragraphing macro to indicate synonymous ways
of invoking a particular mode of operation. Paragraphing macros
can similarly manage grouping of function synopses.
groff's own command-line interface illustrates most specimens of
synopsis syntax one may encounter.
.SY groff
.RB [ \-abcCeEgGijklNpRsStUVXzZ ]
.RB [ \-d\~\c
.IR ctext ]
.RB [ \-d\~\c
.IB string =\c
.IR text ]
.RB [ \-D\~\c
.IR fallback-encoding ]
(and so on similarly)
.RI [ file\~ .\|.\|.]
.YS
.
.
.P
.SY groff
.B \-h
.YS
.
.SY groff
.B \-\-help
.YS
.
.
.P
.SY groff
.B \-v
.RI [ option\~ .\|.\|.\&]
.RI [ file\~ .\|.\|.]
.YS
.
.SY groff
.B \-\-version
.RI [ option\~ .\|.\|.\&]
.RI [ file\~ .\|.\|.]
.YS
Given the foregoing input, groff man produces the following
output.
groff [-abcCeEgGijklNpRsStUVXzZ] [-d ctext]
[-d string=text] [-D fallback-encoding] [-f font-
family] [-F font-directory] [-I inclusion-directory]
[-K input-encoding] [-L spooler-argument] [-m macro-
package] [-M macro-directory] [-n page-number]
[-o page-list] [-P postprocessor-argument]
[-r cnumeric-expression] [-r register=numeric-
expression] [-T output-device] [-w warning-category]
[-W warning-category] [file ...]
groff -h
groff --help
groff -v [option ...] [file ...]
groff --version [option ...] [file ...]
Several features of the above example are of note.
• The empty request (.), which does nothing, vertically spaces
the input file for readability by the document maintainer. Do
not put blank (empty) lines in a man page source document.
Some man(1) programs “squeeze” multiple blank output lines into
one.
• 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 copy-and-paste from the rendered man page to a shell
prompt or text file.
• Option arguments and command operands are presented in italics
(but see subsection “Font style macros” below regarding
terminals) to cue the user that they must be replaced with
appropriate input.
• Symbols that are neither to be typed literally nor replaced at
the user's discretion appear in the roman style; brackets
surround optional arguments, and an ellipsis indicates that the
previous syntactic element may be repeated arbitrarily. Where
whitespace separates optional arguments, a space precedes the
ellipsis.
• The non-breaking adjustable space escape sequence \~ prevents
the output line from breaking within the option brackets; see
subsection “Portability” below.
• The output line continuation escape sequence \c is used with
font style alternation macros to allow all three font styles to
be set without (breakable) space among them; see subsection
“Portability” below.
• The dummy character escape sequence \& follows the ellipsis
when further text is to follow after space on the output line,
keeping its last period from being interpreted as the end of a
sentence because it is followed by characters that are
transparent to end-of-sentence detection, and/or a newline,
which would in turn normally cause the formatter to place
additional inter-sentence space after it. See subsection
“Portability” below.
We might synopsize the standard C library function bsearch(3) as
follows.
.P
.B void *\c
.SY bsearch (
.BI const\~void\~* key ,
.BI const\~void\~* base ,
.BI size_t\~ nmemb ,
.BI int\~(* compar )\c
.B (const\~void\~*, const\~void\~*));
.YS
groff man produces the following result.
void *
bsearch const void *key, const void *base, size_t nmemb,
int (*compar)(const void *, const void *));
Hyperlink macros
Man page cross references like ls(1) are best presented with MR.
Mark email addresses with MT/ME and other sorts of URI with UR/UE.
To hyperlink text, terminals and pager programs must support
ECMA-48 OSC 8 escape sequences (see grotty(1)). When device
support is unavailable or disabled with the U register (see
section “Options” below), groff man renders these URIs between
angle brackets (⟨ ⟩) after the linked text.
MT, ME, UR, and UE are GNU extensions supported by Heirloom
Doctools and mandoc (UR/UE since 1.12.3; MT/ME since 1.14.2) but
not by DWB, Plan 9 (original), or Solaris 10 troffs. Plan 9 from
User Space's troff implements MR.
Prepare arguments to MR, MT, and UR for typesetting; they can
appear in the output. Use special character escape sequences to
encode Unicode basic Latin characters where necessary,
particularly the hyphen-minus. (See subsection “Portability”
below.) URIs can be lengthy; rendering them can result in jarring
adjustment or variations in line length, or troff warnings when
one is longer than an output line. The application of non-
printing break point escape sequences \: after each slash (or
series thereof), and before each dot (or series thereof) is
recommended as a rule of thumb. The former practice avoids
forcing a trailing slash in a URI onto a separate output line, and
the latter helps the reader to avoid mistakenly interpreting a dot
at the end of a line as a period (or multiple dots as an
ellipsis). Thus,
.UR http://\:example\:.com/\:fb8afcfbaebc74e\:.cc
has several potential break points in the URI shown. Consider
adding break points before or after at signs in email addresses,
and question marks, ampersands, and number signs in HTTP(S) URIs.
.MR topic [manual-section [trailing-text]]
(since groff 1.23) Set a man page cross reference as
“topic(manual-section)”. If manual-section is absent, the
package omits the surrounding parentheses. If trailing-
text (typically punctuation) is specified, it follows the
closing parenthesis without intervening space. Hyphenation
is disabled while the cross reference is set. topic is set
in the font specified by the MF string. If manual-section
is present, the cross reference hyperlinks to a URI of the
form “man:topic(manual-section)”.
The output driver
.MR grops 1
produces PostScript from
.I troff
output.
.
The Ghostscript program (\c
.MR gs 1 )
interprets PostScript and PDF.
.MT address
.ME [trailing-text]
Identify address as an RFC 6068 addr-spec for a “mailto:”
URI with the text between the two macro calls as the link
text. An argument to ME is placed after the link text
without intervening space. address may not be visible in
the rendered document if hyperlinks are enabled and
supported by the output driver. If they are not, address
is set in angle brackets after the link text and before
trailing-text. If hyperlinking is enabled but there is no
link text, address is formatted and hyperlinked without
angle brackets.
When rendered by groff to a PostScript 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.”.
.UR uri
.UE [trailing-text]
Identify uri as an RFC 3986 URI hyperlink with the text
between the two macro calls as the link text. An argument
to UE is placed after the link text without intervening
space. uri may not be visible in the rendered document if
hyperlinks are enabled and supported by the output driver.
If they are not, uri is set in angle brackets after the
link text and before trailing-text. If hyperlinking is
enabled but there is no link text, uri is formatted and
hyperlinked without angle brackets.
When rendered by groff to a PostScript device,
The GNU Project of the Free Software Foundation
hosts the
.UR https://\:www\:.gnu\:.org/\:software/\:groff/
.I 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/⟩.”.
If a UR/UE or MT/ME pair occurs in a TP tag and hyperlinking is
unavailable, groff man sets the link target at the beginning of
the indented paragraph, not as part of the tag.
Font style macros
The man macro package is limited in its font styling options,
offering only bold (B), italic (I), and roman. Italic text may
instead render underscored on terminals. SM sets text at a
smaller type size, which differs visually from regular-sized text
only on typesetters. The macros BI, BR, IB, IR, RB, and RI set
their odd- and even-numbered arguments as text in the alternating
styles their names indicate, with no space 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,
and inlined literals.
The default type size and family for typesetters is 10-point
Times, except on the X75-12 and X100-12 devices where the type
size is 12 points. The default style is roman.
.B [text]
Set text in bold. Given no argument, B plants a one-line
input trap; text on the next line, which can be further
formatted with a macro, 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, string, and
register names. In an EX/EE example of interactive I/O
(such as a shell session), set only user input in bold.
.I [text]
Set text in an italic or oblique face. Given no argument,
I plants a one-line input trap; text on the next line,
which can be further formatted with a macro, is set in an
italic or oblique face.
Use italics for file and path names, for environment
variables, for C data types, for enumeration or
preprocessor constants in C, for variant (user-replaceable)
portions of syntax synopses, for the first occurrence
(only) of a technical concept being introduced, for names
of journals and of literary works longer than an article,
and anywhere a parameter requiring replacement by the user
is encountered. An exception involves variant text in a
context already typeset in italics, such as file or path
names with replaceable components; in such cases, follow
the convention of mathematical typography: set the file or
path name in italics as usual but use roman for the variant
part (see IR and RI below), and italics again in running
roman text when referring to the variant material.
.SM [text]
Set text one point smaller than the default type size on
typesetters. Given no argument, SM plants a one-line input
trap; text on the next line, which can be further formatted
with a macro, is set smaller.
Note: terminals render text at normal size instead. Do not
rely upon SM to communicate semantic information distinct
from using roman style at normal size; it is hidden from
readers using such devices.
Observe 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 major works of literature; identifiers for
standards documents or technical reports such as CSTR #54,
RFC 1918, Unicode 16, or POSIX.1-2024; acronyms; and occurrences
after the first of a technical term.
Use italics for emphasis rarely, and bold almost never. Brief
specimens of literal text, such as article titles, inline
examples, mentions of individual characters or short strings, and
(sub)section headings in man pages, are suitable for quotation;
see the \[lq], \[rq], \[oq], and \[cq] escape sequences in
subsection “Portability” below.
Unlike the above font style macros, the font style alternation
macros below set no input traps; they must be given arguments to
have effect. They apply italic corrections as appropriate. If a
space is required within an argument, first consider whether the
same result could be achieved with as much clarity by using
single-style macros on separate input lines. When it cannot,
double-quote an argument containing embedded space characters.
Setting all three different styles within a word presents
challenges; it is possible with the \c and/or \f escape sequences.
See subsection “Portability” below for approaches.
.BI bold-text italic-text ...
Set each argument in bold and italics, alternately.
.BI -r\~ register = numeric-expression
.BR bold-text roman-text ...
Set each argument in bold and roman, alternately.
Set an ellipsis on the math axis with the GNU extension macro
.BR cdots .
.IB italic-text bold-text ...
Set each argument in italics and bold, alternately.
In places where
.IB n th
is allowed,
.IR italic-text roman-text ...
Set each argument in italics and roman, alternately.
Use GNU
.IR pic 's
.B figname
command to change the name of the vbox.
.RB roman-text bold-text ...
Set each argument in roman and bold, alternately.
.I file
is
.RB \[lq] \- \[rq],
.I groff
reads the standard input stream.
.RI roman-text italic-text ...
Set each argument in roman and italics, alternately.
.RI ( tpic
was a fork of AT&T
.I pic
by Tim Morgan of the University of California at Irvine
Horizontal and vertical spacing
The package sets all text inboard of the left edge of the output
medium by the amount of the page offset; see register PO in
section “Options” below. Headers, footers (both set with TH), and
section headings (SH) lie at the page offset. groff man indents
subsection headings (SS) by the amount in the SN register.
Ordinary paragraphs not within an RS/RE inset region are inset by
the amount stored in the BP register; see section “Options” below.
The IN register configures the default indentation amount used by
RS (as the inset-amount), IP, TP, and HP; an overriding argument
is a number plus an optional scaling unit. If no scaling unit is
given, the man package assumes “n”; that is, roughly the width of
a letter “n” in the font current when the macro is called—see
section “Measurements” in groff(7). An indentation specified in a
call to IP, TP, or HP persists until (1) another of these macros
is called with an indentation argument, or (2) SH, SS, or P or its
synonyms is called; these clear the indentation entirely.
The inset amount and indentation are related but distinct
parameters with the same defaults. The former is manipulated by
RS and RE (and by SH and SS, which reset it to the default).
Indentation is controlled by the paragraphing macros (though,
again, SH and SS reset it); it is imposed by the TP, IP, and HP
macros, and cancelled by P and its synonyms. An extensive example
follows.
This ordinary (P) paragraph is not in a relative inset nor does it
possess an indentation.
Now we have created a relative inset with RS and started
another ordinary paragraph with P. We observe that all of
its lines are inset and indented the same; contrast with a
first-line indentation.
tag This tagged paragraph, set with TP, is still within
the RS region, but lines after the first have a
supplementary indentation that the tag lacks.
A paragraph like this one, set with IP, appears to
the reader as also associated with the tag above,
because IP re-uses the previous paragraph's
indentation unless given an argument to change it.
Both the inset amount (RS) and indentation (IP)
affect this paragraph.
┌───────────────────────────────────┐
│ This table is affected both by │
│ the inset amount and indentation. │
└───────────────────────────────────┘
• This indented paragraph is marked with a bullet,
contrasting the inset amount and the indentation;
only the former affects the mark, but both affect
the text of the paragraph.
This ordinary (P) paragraph resets the indentation, but the
inset amount is unchanged.
┌─────────────────────────────┐
│ This table is affected only │
│ by the inset amount. │
└─────────────────────────────┘
Finally, we have ended the relative inset by using RE, which
(because we used only one RS/RE pair) has restored the inset
amount to its initial value. This is an ordinary P paragraph.
Resist the temptation to mock up tabular or multi-column output
with tab characters or the indentation arguments to IP, TP, RS, or
HP; the result may not be comprehensible on an output device you
fail to check, or which is developed in the future. Consider the
table preprocessor tbl(1) instead.
Several macros insert vertical space: SH, SS, TP, P (and its
synonyms), IP, and HP. The default inter-section and inter-
paragraph spacing is 1v for terminals and 0.4v for typesetters.
“v” is a unit of vertical distance, where 1v is the distance
between adjacent text baselines. (The deprecated macro PD can
change this vertical spacing, but we discourage its use.) Between
EX and EE calls, the inter-paragraph spacing is 1v regardless of
output device.
Registers
Registers are described in section “Options” below. They can be
set not only on the command line but in the site man.local file as
well; see section “Files” below.
Strings
The following strings are defined for use in man pages. groff man
supports others for configuration of rendering parameters; see
section “Options” below.
\*R interpolates a special character escape sequence for the
“registered sign” glyph, \(rg, if available, and “(Reg.)”
otherwise.
\*S interpolates an escape sequence setting the type size to
the document default.
\*(lq
\*(rq interpolate special character escape sequences for left and
right double-quotation marks, \(lq and \(rq, respectively.
\*(Tm interpolates a special character escape sequence for the
“trade mark sign” glyph, \(tm, if available, and “(TM)”
otherwise.
A contemporary man page needs none of the above. \*S is
superfluous; type size changes are invisible on terminals, and
macros that change it restore its original value afterward.
Better alternatives exist for the rest; simply use the \[rg],
\[lq], \[rq], and \[tm] special character escape sequences
directly. Unless you are aiming for a pathological level of
portability—perhaps composing a man page for consumption on
simulators of 1980s Unix systems (or Solaris 10 troff, though even
it supports “\(rg”)—avoid using the above strings.
Use of extensions
To ensure that your man page formats reliably on a wide variety of
viewers, write it solely with the macros described in this page
(except for the ones identified as deprecated, which you should
avoid). Macros described as extensions might be unsupported by a
formatter that is important to your audience. Nevertheless,
groff's extensions are present because they perform tasks that are
otherwise difficult or tedious to achieve portably. If you
require an extension but expect your man page to be rendered on a
system that doesn't support it, write a configuration test to
measure a property of the system, and use m4(1), sed(1), or a
similar tool to generate a .man file from a .man.in file, defining
page-local versions of extension macros only where necessary. You
can copy extension macro definitions from groff; see an-ext.tmac
in section “Files” below.
For example, we might put a line
@DEFINE_MR@
in our man document at the end of the “Name” section, test a
system for the availability of the groff man MR macro, remove the
line if the macro is present, and “inline” a definition otherwise,
as follows. (This version is slightly simplified and does not
attempt to disable hyphenation when setting arguments to MR.)
have_MR=$(echo .pm | troff -man 2>&1 | grep 'MR[[:space:]]')
if [ -n "$have_MR" ]
then
sed '/@DEFINE_MR@/d' myprog.man.in > myprog.man
else
sed 's/@DEFINE_MR@/.de MR\
. ie \\\\n(.$=1 .I \\\\$1\
. el .IR \\\\$1 (\\\\$2)\\\\$3\
../' myprog.man.in > myprog.man
fi
(The profusion of backslashes is due to its status as an escape
character in both roff and sed.)
If the foregoing method is too much trouble, you could apply the
radical technique of reading your man page using every formatter
of interest, confirming satisfactory output from each. Test
documentation for syntactic validity and semantic correctness,
just as you would test code.
Portability
An installed man page should contain Unicode basic Latin code
points exclusively. One can maintain it in a more convenient
encoding, using preconv(1) to produce a basic Latin version that
employs special character escape sequences to access code points
necessary in non-English text.
AT&T troff's man package and those of many of its descendants
format man pages using a line length of 65 ens (character cells)
on terminals, whereas groff man uses 80 ens (and mandoc(1) 78).
Readers with low vision may also benefit from the narrower line
length. Inspect your documents with “nroff -t -r LL=65n -man” to
ensure that their output lines don't overrun.
In roff systems, elemental typesetting functions called requests
and escape sequences control formatting operations. A request
appears on a control line. An escape sequence starts with a
backslash (\) and can appear anywhere. However, use of roff
requests (apart from the empty request “.”) risks poor rendering
when a page is processed by non-roff formatters that attempt to
interpret page sources. (Historically, this was commonly
attempted for HTML conversion.) Many of these programs don't
interpret the full roff language (let alone extensions): they may
be incapable of handling numeric expressions, control structures,
or register, string, and macro definitions, causing a document's
contents to be presented incomprehensibly or omitted entirely.
The wise man author quotes multi-word section and subsection
headings; the SH and SS macros of man(7) implementations descended
from Seventh Edition Unix supported six arguments at most. This
restriction also applied to the B, I, SM, and font style
alternation macros.
Exercise restraint with escape sequences as with requests. Some
escape sequences are however required for correct typesetting even
in man pages and usually do not cause portability problems.
Several of these render glyphs corresponding to punctuation code
points in the Unicode basic Latin range (U+0020–U+007F) that are
handled specially in roff input; the escape sequences below must
be used to render them correctly and portably when documenting
material that uses them as literals—namely, any of the set ' - \ ^
` ~ (apostrophe, dash or hyphen-minus, backslash, caret, grave
accent, tilde).
\" Comment. The formatter ignores everything after the
double quote to the end of the input line. Place whole-
line comments on a control line 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 appears to groff as a
single input line. Splitting excessively long input
lines can ease document maintenance.
\% Control hyphenation. The location of this escape
sequence within a word marks a hyphenation point,
supplementing groff's automatic hyphenation patterns.
At the beginning of a word, it suppresses any
hyphenation breaks within except those specified with
\%.
\: Insert a non-printing break point. A word can break at
such a point, but a hyphen glyph is not written to the
output if it does. The remainder of the word is subject
to hyphenation as normal. You can use \: and \% in
combination to control breaking of a file name or URI or
to permit hyphenation only after certain explicit
hyphens within a word. See subsection “Hyperlink
macros” above for an example.
\: is a GNU extension also supported by Heirloom
Doctools troff 050915 (September 2005), mandoc 1.13.1
(2014-08-10), and neatroff (commit 399a4936,
2014-02-17), but not by DWB, Plan 9, or Solaris 10
troffs.
\~ Adjustable non-breaking space. Use this escape sequence
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.
\~ is a GNU extension also supported by Heirloom
Doctools troff 050915 (September 2005), mandoc 1.9.14
(2009-11-16), neatroff (commit 1c6ab0f6e, 2016-09-13),
and Plan 9 from User Space troff (commit 93f8143600,
2022-08-12), but not by DWB or Solaris 10 troffs.
\& Dummy character. Prefix an input line with it to
prevent a dot or apostrophe from being interpreted as
beginning a roff control line. Append \& to an end-of-
sentence punctuation sequence to keep it from being
recognized as such.
\| Thin space (one-sixth em on typesetters, zero-width on
terminals); a non-breaking space. Used primarily in
ellipses (“.\|.\|.”) to space the dots more pleasantly
on typesetters.
\c End a text line without inserting space or attempting a
break. Nothing on the input line after this escape
sequence is formatted. \c is useful when three font
styles are needed in a single word, as in a command
synopsis.
.RB [ \-\-stylesheet=\c
.IR name ]
\c also helps when changing font styles in EX/EE
examples, since they are not filled.
.EX
$ \c
.B groff \-T utf8 \-Z \c
.I file \c
.B | grotty \-i
.EE
Normally, if filling is enabled, the formatter treats
the end of a text line like a space. It checks for the
end of a sentence, and may break the output line (if
not, it inserts an adjustable space). If filling is
disabled, the formatter will break the output line, as
in EX/EE examples. The formatter interprets the next
input line as usual, recognizing control lines,
including macro calls (contrast with \newline).
The \f font selection escape sequence is an alternative
to \c; see below. Using \c to continue a TP paragraph
tag across multiple input lines renders incorrectly with
groff 1.22.3, mandoc 1.14.1, older versions of these
programs, and perhaps with some other formatters.
\e Format the roff escape character on the output; widely
used in man pages to render a backslash 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 explicit \[rs] (“reverse
solidus”) special character escape sequence.
\fB, \fI, \fR, \fP
Switch to bold, italic, roman, or back to the previous
style, respectively. Either \f or \c is needed when
three different font styles are required in a word.
.RB [ \-\-reference\-dictionary=\fI\,name\/\fP ]
.RB [ \-\-reference\-dictionary=\c
.IR name ]
Style escape sequences may be more portable than \c. As
shown above, it is up to you to account for italic
corrections with “\/” and “\,”, which are themselves GNU
extensions, if desired and if supported by your
implementation.
\fP reliably returns to the style in use immediately
preceding the previous \f escape sequence only if no
sectioning, paragraph, example, or style macro calls
have intervened.
As long as at most two styles are needed in a word,
style macros like B and BI usually result in more
readable roff source than \f escape sequences do.
Several special characters are also widely portable. Except for
\-, \[em], and \[ga], AT&T troff did not consistently define the
characters listed below, but its descendants, like DWB, Plan 9, or
Solaris 10 troff, can be made to support them by defining them in
font description files, making them aliases of existing glyphs if
necessary; see groff_font(5). groff's extended notation for
special characters, \[xx], is also supported by mandoc(1),
Heirloom Doctools troff, and neatroff, but not DWB, Plan 9, or
Solaris 10 troffs.
\- Minus sign. \- produces the basic Latin hyphen-minus
(U+002D) specifying Unix command-line options and
frequently used in file names. “-” is a hyphen in roff;
some output devices format it as U+2010 (hyphen).
\[aq] Basic Latin neutral apostrophe. Some output devices format
“'” as a right single quotation mark.
\[oq]
\[cq] Opening (left) and closing (right) single quotation marks.
Use these for paired directional single quotes, ‘like
this’.
\[dq] Basic Latin quotation mark (double quote). Employ it in
macro calls to work around interpretation of ‘"’ as an
argument delimiter.
.TP
.BI "split \[dq]" text \[dq]
\[lq]
\[rq] Left and right double quotation marks. Use these for
paired directional double quotes, “like this”.
\[em] Em dash. Use for an interruption—such as this one—in a
sentence.
\[en] En dash. Use to separate the ends of a range, as between
numbers; for example, “the digits 1–9”.
\[ga] Basic Latin grave accent. Some output devices format “`”
as a left single quotation mark.
\[ha] Basic Latin circumflex accent (“hat”). Some output devices
format “^” as U+02C6 (modifier letter circumflex accent).
\[rs] Reverse solidus (backslash). The backslash is the default
escape character in the roff language, so it does not
represent itself in output. Also see \e above.
\[ti] Basic Latin tilde. Some output devices format “~” as
U+02DC (small tilde).
For maximum portability, avoid escape sequences (including special
characters) not listed above.
Hooks
Two macros, both GNU extensions, are called internally by the
groff man package to format page headers and footers and can be
redefined by the administrator in a site's man.local file (see
section “Files” below). The presentation of TH above describes
the default headers and footers. Because these macros are hooks
for groff man internals, man pages have no reason to call them.
Such hook definitions typically consist of “sp” and “tl” requests.
PT furthermore has the responsibility of emitting a PDF bookmark
after writing the first page header in a document. Consult the
existing implementations in an.tmac when drafting replacements.
.BT Set the page footer text (“bottom trap”).
.PT Set the page header text (“page trap”).
To remove a page header or footer entirely, define the appropriate
macro as empty rather than deleting it.
Deprecated features
Use of the following in man pages for public distribution is
discouraged.
.AT [system [release]]
Alter the footer for use with legacy AT&T man pages,
overriding any definition of the footer-inside argument to
TH. This macro exists only to render man pages from
historical systems.
The inside footer is populated per the value of system.
3 7th edition (default)
4 System III
5 System V
The optional release argument specifies the release number,
as in “System V Release 3”.
.DT Reset tab stops to the default (every 0.5i [inches]).
Use of this presentation-oriented macro is deprecated. It
translates poorly to HTML, under which exact space control
and tabulation are not readily available. Thus,
information or distinctions that you use tab stops to
express are likely to be lost. If you feel tempted to
change the tab stops such that calling this macro later to
restore them is desirable, consider composing a table using
tbl(1) instead.
.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.
Use of this quasi-semantic macro, an extension whose name
originated in DWB troff, is deprecated; groff's
implementation differs. Neither can easily be used to
annotate options that take optional arguments or options
whose arguments have internal structure (such as a mixture
of literal and variable components). One could work around
these limitations with font selection escape sequences, but
font style alternation macros are preferable; they are more
flexible and perform italic corrections on typesetters.
.PD [vertical-space]
Configure the amount of vertical space between paragraphs
or (sub)sections. The optional argument vertical-space
specifies the amount; the default scaling unit is “v”.
Without an argument, inter-paragraph spacing resets to its
default value; see subsection “Horizontal and vertical
spacing” above.
Use of this presentation-oriented 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.
.SB [text]
Set text in bold and (on typesetters) one point smaller
than the default type size. Given no argument, SB plants a
one-line input trap; text on the next line, which can be
further formatted with a macro, is set smaller and in bold.
Use of this macro, an extension originating in SunOS 4.0
troff, is deprecated. SM without an argument, followed
immediately by “B text”, produces the same output more
portably. The macros' order is interchangeable; put text
with the latter.
Note: terminals render text in bold at the normal size
instead. Do not rely upon SB to communicate semantic
information distinct from using bold style at normal size;
it is hidden from readers using such devices.
.UC [version]
Alter the footer for use with legacy BSD man pages,
overriding any definition of the footer-inside argument to
TH. This macro exists only to render man pages from
historical systems.
The inside footer is populated per the value of version.
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
M. Douglas McIlroy ⟨m.douglas.mcilroy@dartmouth.edu⟩ designed,
implemented, and documented the AT&T man macros for Unix Version 7
(1979) and employed them to edit Volume 1 of its Programmer's
Manual, a compilation of all man pages supplied by the system.
The package supported the macros listed in this page not described
as extensions, except P and the deprecated AT and UC. It
documented no registers and defined only R and S strings.
UC appeared in 3BSD (1980). Unix System III (1980) introduced P
and exposed the registers IN and LL, which had been internal to
Seventh Edition Unix man. PWB/Unix 2.0 (1980) added the Tm
string. 4BSD (1980) added lq and rq strings. SunOS 2.0 (1985)
recognized C, D, P, and X registers. 4.3BSD (1986) added AT and
P. Ninth Edition Unix (1986) introduced EX and EE. SunOS 4.0
(1988) added SB.
Except for EX/EE, James Clark implemented the foregoing features
in early versions of groff. Later, groff 1.20 (2009) resurrected
EX/EE and originated SY/YS, TQ, MT/ME, and UR/UE. Plan 9 from
User Space's troff introduced MR in 2020.
The following groff options set registers (with -r) and strings
(with -d) recognized and used by the man macro package. To ensure
rendering consistent with output device capabilities and reader
preferences, man pages should never manipulate them.
-dAD=adjustment-mode
Set line adjustment to adjustment-mode, which is typically
“b” for adjustment to both margins (the default), or “l”
for left alignment (ragged right margin). Any valid
argument to groff's “ad” request may be used. See groff(7)
for less-common choices.
-rBP=base-paragraph-inset
Set the inset amount for ordinary paragraphs not within an
RS/RE inset. The default is 5n.
-rcR=1 Enable continuous rendering. Output is not paginated;
instead, one (potentially very long) page is produced.
This is the default for terminal and HTML devices. Use
-rcR=0 to disable it on terminals; on HTML devices, it
cannot be disabled.
-rC1 Number output pages consecutively, in strictly increasing
sequence, rather than resetting the page number to 1 (or
the value of register P) with each new man document.
-rCHECKSTYLE=n
Report problems with usage of this macro package exhibited
by the input at verbosity level n, where n is an integer in
the range 0–3, inclusive; 0 disables the messages and is
the default. This feature is a development and debugging
aid for man page maintainers; the problems diagnosed, and
range and meanings of the supported levels, are subject to
change.
-rCS=1 Set section headings (the argument(s) to SH) in full
capitals. This transformation is off by default because it
discards lettercase distinctions.
-rCT=1 Set the man page identifier (the first argument to TH) in
full capitals in headers and footers. This transformation
is off by default because it discards lettercase
distinctions.
-rD1 Enable double-sided layout, formatting footers for even and
odd pages differently; see the description of TH in
subsection “Document structure macros” above.
-rFT=footer-distance
Set distance of the footer relative to the bottom of the
page to footer-distance; this amount is always negative.
At one half-inch above this location, the page text is
broken before writing the footer. Ignored if continuous
rendering is enabled. The default is “-0.5i - 1v”.
-dHF=heading-font
Select the font used for section and subsection headings;
the default is “B” (bold style of the default family). Any
valid argument to groff's “ft” request may be used. See
groff(7).
-rHY=0 Disable automatic hyphenation. Normally, it is
enabled (1). The hyphenation mode is determined by the
groff locale; see section “Localization“ of groff(7).
-rIN=standard-indentation
Set the default indentation amount used by IP, TP, and HP,
and the inset amount used by RS. The default is 7n on
terminals and 7.2n on typesetters. Use only integer
multiples of unit “n” on terminals for consistent
indentation.
-rLL=line-length
Set line length; the default is 80n on terminals and 6.5i
on typesetters.
-rLT=title-length
Set the line length for titles. (“Titles” is the roff term
for headers and footers.) By default, it is set to the
line length (see -rLL above).
-dMF=man-page-topic-font
Select the font used for man page identifiers in TH calls
and topics named in MR calls; the default is “I” (italic
style of the default family). Any valid argument to
groff's “ft” request may be used. If the MF string ends in
“I”, the package assumes it to be an oblique typeface, and
applies italic corrections before and after man page topics
and identifiers.
-rPn Start enumeration of pages at n. The default is 1.
-rPO=page-offset
Set page offset; the default is 0 on terminals and 1i on
typesetters.
-rStype-size
Use type-size for the document's body text; acceptable
values are 10, 11, or 12 points. See subsection “Font
style macros” above for the default.
-rSN=subsection-indentation
Set indentation of subsection headings to subsection-
indentation. The default is 3n.
-rTS=separation
Require the given separation between a TP paragraph's tag
and its body. The default is 2n.
-rU0 Disable generation of URI hyperlinks in output drivers
capable of them, making the arguments to MT and UR calls
visible as formatted text. grohtml(1), gropdf(1), and
grotty(1) enable hyperlinks by default (the last only if
not in its legacy output mode).
-rXp Number successors of page p as pa, pb, pc, and so forth.
The register tracking the suffixed page letter uses format
“a” (see the “af” request in groff(7)). For example, the
option -rX2 produces the following page numbers: 1, 2, 2a,
2b, ..., 2aa, 2ab, and so on.
/usr/local/share/groff/1.23.0/tmac/an.tmac
Most man macros are defined in this file. It also loads
extensions from an-ext.tmac (see below).
/usr/local/share/groff/1.23.0/tmac/andoc.tmac
This brief groff program detects whether the man or mdoc
macro package is 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, before any
other macros. A man program or a user typing, for example,
“groff -mandoc page.1”, need not know which package the
file page.1 uses. Multiple man pages, in either format,
can be handled; andoc reloads each macro package as
necessary. Page-local redefinitions of names used by the
man or mdoc packages prior to TH or Dd calls are
“clobbered” by the reloading process. If you want to
provide your own definition of an extension macro to ensure
its availability, the an-ext.tmac entry below offers
advice.
/usr/local/share/groff/1.23.0/tmac/an-ext.tmac
Definitions of macros described above as extensions (and
not deprecated) are contained in this file; in some cases,
they are simpler versions of definitions appearing in
an.tmac, and are ignored if the formatter is GNU troff.
They are written to be compatible with AT&T troff and
permissively licensed—not copylefted. To reduce the risk
of name space collisions, string and register names begin
only with “m”. We encourage man page authors who are
concerned about portability to legacy Unix systems to copy
these definitions into their pages, and maintainers of
troff implementations or work-alike systems that format man
pages to re-use them. To ensure reliable rendering, define
them after your page calls TH; see the discussion of andoc
.tmac above. Further, it is wise to define such page-local
macros (if at all) after the “Name” section to accommodate
timid makewhatis(8) or mandb(8) implementations that easily
give up scanning for indexing material.
/usr/local/share/groff/1.23.0/tmac/man.tmac
is a wrapper enabling the package to be loaded with the
option “-m man”.
/usr/local/share/groff/1.23.0/tmac/mandoc.tmac
is a wrapper enabling andoc.tmac to be loaded with the
option “-m mandoc”.
/usr/local/share/groff/site-tmac/man.local
Put site-local changes and customizations into this file.
.\" Put only one space after the end of a sentence.
.ss 12 0 \" See groff(7).
.\" Keep pages narrow even on wide terminals.
.if n .if \n[LL]>80n .nr LL 80n
On multi-user systems, it is more considerate to users
whose preferences may differ from the administrator's to be
less aggressive with such settings, or to permit their
override with a user-specific man.local file. Place the
requests below at the end of the site-local file to
manifest courtesy.
.soquiet \V[XDG_CONFIG_HOME]/man.local
.soquiet \V[HOME]/.man.local
However, a security-sandboxed man(1) program may lack
permission to open such files.
Some tips on composing and troubleshooting your man pages follow.
• What's the difference between a man page topic and identifier?
A single man page may document several related but distinct
topics. For example, printf(3) and fprintf(3) are often
presented together. Moreover, multiple programming languages
have functions named “printf”, and may document these in a man
page. The identifier is intended to (with the section) uniquely
identify a page on the system; it may furthermore correspond
closely to the file name of the document.
The man(1) librarian makes access to man pages convenient by
resolving topics to man page identifiers. Thus, you can type
“man fprintf”, and other pages can refer to it, without knowing
whether the installed document uses “printf”, “fprintf”, or even
“c_printf” as its identifier.
• Some ASCII characters look funny or copy and paste wrong.
On devices with large glyph repertoires, like UTF-8-capable
terminals and PDF, GNU troff, like AT&T troff before it, maps
several keycaps to code points outside the Unicode basic Latin
range (historically “ASCII”) because that usually results in
better typography in the general case. When documenting
GNU/Linux command or C language syntax, however, this
translation is sometimes not desirable.
To get a “literal”... ...should be input.
────────────────────────────────────────────
' \[aq]
- \-
\ \[rs]
^ \[ha]
` \[ga]
~ \[ti]
────────────────────────────────────────────
If a neutral double quote (") is needed in a macro argument, you
can use \[dq] to get it. Do not use \[aq] for an ordinary
apostrophe (as in “can't”) or \- for an ordinary hyphen (as in
“word-aligned”).
• Do I ever need to use an empty macro argument ("")?
Probably not. When this seems necessary, often a shorter or
clearer alternative is available.
Instead of... ...should be considered.
────────────────────────────────────────────────────────────────
.TP "" .TP
────────────────────────────────────────────────────────────────
.BI "" italic-text bold-text .IB italic-text bold-text
────────────────────────────────────────────────────────────────
.TH foo 1 "" "foo 1.2.3" .TH foo 1 yyyy-mm-dd "foo 1.2.3"
────────────────────────────────────────────────────────────────
.IP "" 4n .IP
────────────────────────────────────────────────────────────────
.IP "" 4n .RS 4n
paragraph .P
... paragraph
... .RE
────────────────────────────────────────────────────────────────
.B one two "" three .B one two three
In the title heading (TH), the date of the page's last revision
is more important than packaging information; it should not be
omitted. Ideally, a page maintainer keeps both up to date.
IP is sometimes ill-understood and misused, especially when no
mark argument is supplied—an indentation argument is not
required. By setting an explicit indentation, you may be
overriding the reader's preference as set with the -rIN option.
If your page renders adequately without one, use the simpler
form. If you need to indent multiple (unmarked) paragraphs,
consider setting an inset region with RS and RE instead.
In the last example, the empty argument does have a subtly
different effect than its suggested replacement: the empty
argument causes an additional space character to be interpolated
between the arguments “two” and “three”—but it is a regular
breaking space, so it can be discarded at the end of an output
line. It is better not to be subtle, particularly with space,
which can be overlooked in source and rendered forms.
• RS doesn't indent relative to my indented paragraph.
The RS macro determines the inset amount, the position at which
an ordinary paragraph (P and its synonyms) is set; the value of
the IN register determines its default amount. This register
also determines the default indentation used by IP, TP, and HP.
To create an inset 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 ordinary
(P) paragraph.
Another approach to tagged paragraphs places an RS call
immediately after the tag; this also forces a break regardless
of the tag's width, which some authors prefer. Follow-up
paragraphs under the tag can then be set with P instead of IP.
Remember to use RE to end the indented region before starting
the next tagged paragraph (at the appropriate nesting level).
• RE doesn't move the inset back to the expected level.
RE takes an inset level as an argument, unlike RS's inset
amount. “.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.
The SH and SS sectioning macros clear relative insets; RE calls
have no effect until RS is used again.
• Do I need to keep typing the indentation in a series of IP
calls?
Not if you don't want to change it. Review subsection
“Horizontal and vertical spacing” above.
Instead of... ...should be considered.
─────────────────────────────────────────────
.IP \[bu] 4n .IP \[bu] 4n
paragraph paragraph
.IP \[bu] 4n .IP \[bu]
another-paragraph another-paragraph
─────────────────────────────────────────────
• Why doesn't the package provide a string to insert an ellipsis?
Examples of ellipsis usage are shown above, in subsection
“Synopsis macros”. The idiomatic roff ellipsis is three dots
(periods) with thin space escape sequences \| internally
separating them. Since dots both begin control lines and are
candidate end-of-sentence characters, however, it is sometimes
necessary to prefix and/or suffix an ellipsis with the dummy
character escape sequence \&. That fact stands even if a string
is defined to contain the sequence; further, if the string ends
with \&, end-of-sentence detection is defeated when you use the
string at the end of an actual sentence. (Ending a sentence
with an ellipsis is often poor style, but not always.) A
hypothetical string EL that contained an ellipsis, but not the
trailing dummy character \&, would then need to be suffixed with
the latter when not ending a sentence.
Instead of... ...do this.
──────────────────────────────────────────────────
.ds EL \&.\|.\|. Arguments are
Arguments are .IR src-file\~ .\|.\|.\&
.IR src-file\~ \*(EL\& .IR dest-dir .
.IR dest-dir .
──────────────────────────────────────────────────
The first column practices a false economy; the savings in
typing is offset by the cost of obscuring even the suggestion of
an ellipsis to a casual reader of the source document, and
reduced portability to non-roff man page formatters that cannot
handle string definitions.
Unicode defines an ellipsis code point, and some fonts have an
ellipsis glyph, which some man pages have accessed non-portably
with the font-dependent \N escape sequence. We discourage their
use; on terminals, they may crowd the dots into a half-width
character cell, and do not render at all if the output device
lacks the glyph. In synopses, missing ellipses can mislead the
reader. Dots and space are universally supported.
• When and how should I use quotation marks?
As noted above in subsection “Font style macros”, apply
quotation marks to “brief specimens of literal text, such as
article titles, inline examples, mentions of individual
characters or short strings, and (sub)section headings in man
pages”. Multi-word literals, such as Unix commands with
arguments, when set inline (as opposed to displayed between EX
and EE), should be quoted to ensure that the boundaries of the
literal are clear even when the material is stripped of font
styling by, for example, copy-and-paste operations. groff,
Heirloom Doctools troff, neatroff, and mandoc support all of the
special characters \[oq], \[cq], \[lq], \[rq], \[aq], and \[dq]
described in subsection “Portability” above. DWB, Plan 9, and
Solaris 10 troffs do not.
Historically, man pages used ` and ' exclusively for directional
single quotation marks. However, in recent years, some
distributors of groff have chosen to override the meanings of
these characters in man pages, remapping them to their Unicode
Basic Latin code points. Unfortunately, ` and ' are the only
reliable means of obtaining directional single quotation marks
in AT&T troff; in that implementation, often no special
character escape sequences exist to obtain them. Further, AT&T
troff's special character identifiers, like its font names, were
device-specific. To achieve quotation portably in man pages
rendered both by AT&T and more modern troffs, consider adding a
preamble to your page after the TH call as follows.
.ie \n(.g \{\
. ds oq \[oq]\"
. ds cq \[cq]\"
.\}
.el \{\
. ds oq `\"
. ds cq '\"
.\}
You must then use the \* escape sequence to interpolate the
quotation mark strings.
The command
.RB \*(oq "while !\& git pull; do sleep 10; done" \*(cq
retries an update from the repository until it succeeds.
If this procedure seems complex, petition your distributor to
revert their remapping of the ` and ' characters.
• Escape sequences of the form \[xx] don't format correctly.
The \[xx] special character escape sequence is a GNU troff
extension also supported by mandoc, Heirloom Doctools troff, and
neatroff. DWB, Plan 9, and Solaris 10 troffs don't implement
it. If your man page requires portability to these formatters,
spell such escape sequences as “\(xx”; no closing parenthesis is
used. xx must be exactly two characters; groff_char(7) lists
portable special character identifiers.
James Clark wrote the initial GNU implementation of the man macro
package. Later, Werner Lemberg ⟨wl@gnu.org⟩ supplied the S, LT,
and cR registers, the last a 4.3BSD-Reno mdoc(7) feature. Larry
Kollar ⟨kollar@alltel.net⟩ added the FT, HY, and SN registers; the
HF string; and the PT and BT macros in groff 1.19 (2003). Lemberg
and Eric S. Raymond ⟨esr@thyrsus.com⟩ contributed EX/EE, MT/ME,
UR/UE, TQ, and an early version of the SY/YS macros to groff 1.20
(2009). G. Branden Robinson ⟨g.branden.robinson@gmail.com⟩
implemented the AD and MF strings; CS, CT, and U registers; and
the MR macro for groff 1.23 (2023), and the BP, PO, and TS
registers and a revised implementation of the SY/YS macros for
groff 1.24 (2025).
This document was originally written for the Debian GNU/Linux
system by Susan G. Kleinmann ⟨sgk@debian.org⟩. It was corrected
and updated by Lemberg and Robinson. The extension macros were
documented by Raymond and Robinson. Raymond also originated the
portability section, to which Ingo Schwarze ⟨schwarze@usta.de⟩
contributed most of the material on escape sequences.
tbl(1), eqn(1), and refer(1) are preprocessors used with man
pages. man(1) describes the man page librarian on your system.
groff_mdoc(7) details the groff version of BSD's alternative macro
package for man pages.
groff_man(7), groff(7), groff_char(7)
This page is part of the groff (GNU troff) project. Information
about the project can be found at
⟨http://www.gnu.org/software/groff/⟩. If you have a bug report for
this manual page, see ⟨http://www.gnu.org/software/groff/⟩. This
page was obtained from the project's upstream Git repository
⟨https://git.savannah.gnu.org/git/groff.git⟩ on 2025-08-11. (At
that time, the date of the most recent commit that was found in
the repository was 2025-08-09.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
groff 1.23.0.3821-a8b3f 2025-08-09 groff_man_style(7)
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