groff_man_style(7)

Name
groff_man_style - GNU roff man page tutorial and style guide

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

Description
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 hanging paragraph | 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. Square brackets surround optional macro arguments. 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]]] Break the page, reset the page number to 1 (unless the -rC1 option is given), and use the arguments to 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 (...). groff man suppresses headers and footers in HTML output.

    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 source document, in ISO 8601 format (YYYY-MM-DD), 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 supplemental inter-sentence space applied. If the amount of supplemental 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 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, reducing it to that of inset-level (or by 1 if not specified) and restoring the corresponding inset amount.

  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 can continue the indented content of a narrative started with TP, or present an itemized or ordered list. If a paragraphing macro has been called since SH or SS, all except 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, hyphenation, and adjustment to (configured) defaults, and the font style to roman.

.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 151218) and mandoc (since 1.14.5) but not by DWB, Plan 9, or Solaris 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 (since Git snapshot 151218) and mandoc (since 1.14.5) support these GNU extensions; DWB, Plan 9, and Solaris 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, the package 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; see subsection “Portability” below regarding blank lines.

•   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 supplemental 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 troff (since Git snapshot 151218) and mandoc (UR/UE since 1.12.3; MT/ME since 1.14.2) but not by DWB, Plan 9 (original), or Solaris 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, except when address appears as a TP paragraph tag.

    When rendered by groff to a PostScript device,

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

    formats 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, except when uri appears as a TP paragraph tag.

    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 .

    formats 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, unless there is no link text.

  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. They then enable no-space mode; see groff(7). 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 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
GNU troff expects its input to contain Unicode basic Latin code points exclusively. One can maintain it in a more convenient encoding, using preconv(1), as with groff(1)'s -k option, to generate a basic Latin version that employs special character escape sequences to access other glyphs.

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 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 almost 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. If your document uses formatter requests, or escape sequences not shown below, it accepts responsibility for restoring formatter state to what the man macro package expects.

Do not put blank (empty) lines in a man page source document. They can produce excessive space in the output, or less than is attempted; some man(1) programs “squeeze” multiple blank output lines into one.

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 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 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 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 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 interface 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. Unix System V (1988) incorporated the lq and rq strings.

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, and incorporated the lq and rq strings in 2025.

Options
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.

Files

/usr/share/groff/1.24.1/tmac/an.tmac
    Most man macros are defined in this file. It also loads extensions from an-ext.tmac (see below).

/usr/share/groff/1.24.1/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/share/groff/1.24.1/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/share/groff/1.24.1/tmac/man.tmac
    is a wrapper enabling the package to be loaded with the option “-m man”.

/usr/share/groff/1.24.1/tmac/mandoc.tmac
    is a wrapper enabling andoc.tmac to be loaded with the option “-m mandoc”.

/usr/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.

Notes
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 troffs do not. Interpolating the strings \*(lq and \*(rq portably yields directional double quotation marks, if available, in all these formatters (though neatroff does not supply a man macro package), but they cannot reliably be used in macro arguments.

    Obtaining directional single quotation marks is more of a challenge. Historically, man pages used ` and ', which troff rendered on typesetters as ‘ and ’, exclusively for them. 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 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.

Authors
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 (2026).

Susan G. Kleinmann (sgk@debian.org) wrote the initial version of this document for the Debian GNU/Linux system. Lemberg imported it to groff. He and Robinson revised and updated it. Raymond and Robinson documented the extension macros. Raymond also originated the portability section, to which Ingo Schwarze (schwarze@usta.de) contributed most of the material on escape sequences.

See also
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)