xref: /openbsd-src/share/man/man7/man.7 (revision 66ae7cc0c0aabb158df4446965606366ddc242f9)
1.\"	$OpenBSD: man.7,v 1.27 2012/02/26 19:41:27 schwarze Exp $
2.\"
3.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4.\" Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
5.\"
6.\" Permission to use, copy, modify, and distribute this software for any
7.\" purpose with or without fee is hereby granted, provided that the above
8.\" copyright notice and this permission notice appear in all copies.
9.\"
10.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17.\"
18.Dd $Mdocdate: February 26 2012 $
19.Dt MAN 7
20.Os
21.Sh NAME
22.Nm man
23.Nd legacy formatting language for manual pages
24.Sh DESCRIPTION
25Traditionally, the
26.Nm man
27language has been used to write
28.Ux
29manuals for the
30.Xr man 1
31utility.
32It supports limited control of presentational details like fonts,
33indentation and spacing.
34This reference document describes the structure of manual pages
35and the syntax and usage of the man language.
36.Pp
37.Bf -emphasis
38Do not use
39.Nm
40to write your manuals:
41.Ef
42It lacks support for semantic markup.
43Use the
44.Xr mdoc 7
45language, instead.
46.Pp
47In a
48.Nm
49document, lines beginning with the control character
50.Sq \&.
51are called
52.Dq macro lines .
53The first word is the macro name.
54It usually consists of two capital letters.
55For a list of available macros, see
56.Sx MACRO OVERVIEW .
57The words following the macro name are arguments to the macro.
58.Pp
59Lines not beginning with the control character are called
60.Dq text lines .
61They provide free-form text to be printed; the formatting of the text
62depends on the respective processing context:
63.Bd -literal -offset indent
64\&.SH Macro lines change control state.
65Text lines are interpreted within the current state.
66.Ed
67.Pp
68Many aspects of the basic syntax of the
69.Nm
70language are based on the
71.Xr roff 7
72language; see the
73.Em LANGUAGE SYNTAX
74and
75.Em MACRO SYNTAX
76sections in the
77.Xr roff 7
78manual for details, in particular regarding
79comments, escape sequences, whitespace, and quoting.
80.Sh MANUAL STRUCTURE
81Each
82.Nm
83document must contain the
84.Sx \&TH
85macro describing the document's section and title.
86It may occur anywhere in the document, although conventionally it
87appears as the first macro.
88.Pp
89Beyond
90.Sx \&TH ,
91at least one macro or text line must appear in the document.
92.Pp
93The following is a well-formed skeleton
94.Nm
95file for a utility
96.Qq progname :
97.Bd -literal -offset indent
98\&.TH PROGNAME 1 2009-10-10
99\&.SH NAME
100\efBprogname\efR \e(en a description goes here
101\&.\e\(dq .SH LIBRARY
102\&.\e\(dq For sections 2 & 3 only.
103\&.\e\(dq Not used in OpenBSD.
104\&.SH SYNOPSIS
105\efBprogname\efR [\efB\e-options\efR] arguments...
106\&.SH DESCRIPTION
107The \efBfoo\efR utility processes files...
108\&.\e\(dq .SH IMPLEMENTATION NOTES
109\&.\e\(dq Not used in OpenBSD.
110\&.\e\(dq .SH RETURN VALUES
111\&.\e\(dq For sections 2, 3, & 9 only.
112\&.\e\(dq .SH ENVIRONMENT
113\&.\e\(dq For sections 1, 6, 7, & 8 only.
114\&.\e\(dq .SH FILES
115\&.\e\(dq .SH EXIT STATUS
116\&.\e\(dq For sections 1, 6, & 8 only.
117\&.\e\(dq .SH EXAMPLES
118\&.\e\(dq .SH DIAGNOSTICS
119\&.\e\(dq For sections 1, 4, 6, 7, & 8 only.
120\&.\e\(dq .SH ERRORS
121\&.\e\(dq For sections 2, 3, & 9 only.
122\&.\e\(dq .SH SEE ALSO
123\&.\e\(dq .BR foo ( 1 )
124\&.\e\(dq .SH STANDARDS
125\&.\e\(dq .SH HISTORY
126\&.\e\(dq .SH AUTHORS
127\&.\e\(dq .SH CAVEATS
128\&.\e\(dq .SH BUGS
129\&.\e\(dq .SH SECURITY CONSIDERATIONS
130\&.\e\(dq Not used in OpenBSD.
131.Ed
132.Pp
133The sections in a
134.Nm
135document are conventionally ordered as they appear above.
136Sections should be composed as follows:
137.Bl -ohang -offset indent
138.It Em NAME
139The name(s) and a short description of the documented material.
140The syntax for this is generally as follows:
141.Pp
142.D1 \efBname\efR \e(en description
143.It Em LIBRARY
144The name of the library containing the documented material, which is
145assumed to be a function in a section 2 or 3 manual.
146For functions in the C library, this may be as follows:
147.Pp
148.D1 Standard C Library (libc, -lc)
149.It Em SYNOPSIS
150Documents the utility invocation syntax, function call syntax, or device
151configuration.
152.Pp
153For the first, utilities (sections 1, 6, and 8), this is
154generally structured as follows:
155.Pp
156.D1 \efBname\efR [-\efBab\efR] [-\efBc\efR\efIarg\efR] \efBpath\efR...
157.Pp
158For the second, function calls (sections 2, 3, 9):
159.Pp
160.D1 \&.B char *name(char *\efIarg\efR);
161.Pp
162And for the third, configurations (section 4):
163.Pp
164.D1 \&.B name* at cardbus ? function ?
165.Pp
166Manuals not in these sections generally don't need a
167.Em SYNOPSIS .
168.It Em DESCRIPTION
169This expands upon the brief, one-line description in
170.Em NAME .
171It usually contains a break-down of the options (if documenting a
172command).
173.It Em IMPLEMENTATION NOTES
174Implementation-specific notes should be kept here.
175This is useful when implementing standard functions that may have side
176effects or notable algorithmic implications.
177.It Em RETURN VALUES
178This section documents the return values of functions in sections 2, 3, and 9.
179.It Em ENVIRONMENT
180Documents any usages of environment variables, e.g.,
181.Xr environ 7 .
182.It Em FILES
183Documents files used.
184It's helpful to document both the file name and a short description of how
185the file is used (created, modified, etc.).
186.It Em EXIT STATUS
187This section documents the command exit status for
188section 1, 6, and 8 utilities.
189Historically, this information was described in
190.Em DIAGNOSTICS ,
191a practise that is now discouraged.
192.It Em EXAMPLES
193Example usages.
194This often contains snippets of well-formed,
195well-tested invocations.
196Make sure that examples work properly!
197.It Em DIAGNOSTICS
198Documents error conditions.
199This is most useful in section 4 manuals.
200Historically, this section was used in place of
201.Em EXIT STATUS
202for manuals in sections 1, 6, and 8; however, this practise is
203discouraged.
204.It Em ERRORS
205Documents error handling in sections 2, 3, and 9.
206.It Em SEE ALSO
207References other manuals with related topics.
208This section should exist for most manuals.
209.Pp
210.D1 \&.BR bar \&( 1 \&),
211.Pp
212Cross-references should conventionally be ordered
213first by section, then alphabetically.
214.It Em STANDARDS
215References any standards implemented or used, such as
216.Pp
217.D1 IEEE Std 1003.2 (\e(lqPOSIX.2\e(rq)
218.Pp
219If not adhering to any standards, the
220.Em HISTORY
221section should be used.
222.It Em HISTORY
223A brief history of the subject, including where support first appeared.
224.It Em AUTHORS
225Credits to the person or persons who wrote the code and/or documentation.
226Authors should generally be noted by both name and email address.
227.It Em CAVEATS
228Common misuses and misunderstandings should be explained
229in this section.
230.It Em BUGS
231Known bugs, limitations, and work-arounds should be described
232in this section.
233.It Em SECURITY CONSIDERATIONS
234Documents any security precautions that operators should consider.
235.El
236.Sh MACRO OVERVIEW
237This overview is sorted such that macros of similar purpose are listed
238together, to help find the best macro for any given purpose.
239Deprecated macros are not included in the overview, but can be found
240in the alphabetical reference below.
241.Ss Page header and footer meta-data
242.Bl -column "PP, LP, P" description
243.It Sx TH Ta set the title: Ar title section date Op Ar source Op Ar volume
244.It Sx AT Ta display AT&T UNIX version in the page footer (<= 1 argument)
245.It Sx UC Ta display BSD version in the page footer (<= 1 argument)
246.El
247.Ss Sections and paragraphs
248.Bl -column "PP, LP, P" description
249.It Sx SH Ta section header (one line)
250.It Sx SS Ta subsection header (one line)
251.It Sx PP , LP , P Ta start an undecorated paragraph (no arguments)
252.It Sx RS , RE Ta reset the left margin: Op Ar width
253.It Sx IP Ta indented paragraph: Op Ar head Op Ar width
254.It Sx TP Ta tagged paragraph: Op Ar width
255.It Sx HP Ta hanged paragraph: Op Ar width
256.It Sx \&br Ta force output line break in text mode (no arguments)
257.It Sx \&sp Ta force vertical space: Op Ar height
258.It Sx fi , nf Ta fill mode and no-fill mode (no arguments)
259.It Sx in Ta additional indent: Op Ar width
260.El
261.Ss Physical markup
262.Bl -column "PP, LP, P" description
263.It Sx B Ta boldface font
264.It Sx I Ta italic font
265.It Sx R Ta roman (default) font
266.It Sx SB Ta small boldface font
267.It Sx SM Ta small roman font
268.It Sx BI Ta alternate between boldface and italic fonts
269.It Sx BR Ta alternate between boldface and roman fonts
270.It Sx IB Ta alternate between italic and boldface fonts
271.It Sx IR Ta alternate between italic and roman fonts
272.It Sx RB Ta alternate between roman and boldface fonts
273.It Sx RI Ta alternate between roman and italic fonts
274.El
275.Sh MACRO REFERENCE
276This section is a canonical reference to all macros, arranged
277alphabetically.
278For the scoping of individual macros, see
279.Sx MACRO SYNTAX .
280.Ss \&AT
281Sets the volume for the footer for compatibility with man pages from
282.Tn AT&T UNIX
283releases.
284The optional arguments specify which release it is from.
285.Ss \&B
286Text is rendered in bold face.
287.Pp
288See also
289.Sx \&I
290and
291.Sx \&R .
292.Ss \&BI
293Text is rendered alternately in bold face and italic.
294Thus,
295.Sq .BI this word and that
296causes
297.Sq this
298and
299.Sq and
300to render in bold face, while
301.Sq word
302and
303.Sq that
304render in italics.
305Whitespace between arguments is omitted in output.
306.Pp
307Examples:
308.Pp
309.Dl \&.BI bold italic bold italic
310.Pp
311The output of this example will be emboldened
312.Dq bold
313and italicised
314.Dq italic ,
315with spaces stripped between arguments.
316.Pp
317See also
318.Sx \&IB ,
319.Sx \&BR ,
320.Sx \&RB ,
321.Sx \&RI ,
322and
323.Sx \&IR .
324.Ss \&BR
325Text is rendered alternately in bold face and roman (the default font).
326Whitespace between arguments is omitted in output.
327.Pp
328See
329.Sx \&BI
330for an equivalent example.
331.Pp
332See also
333.Sx \&BI ,
334.Sx \&IB ,
335.Sx \&RB ,
336.Sx \&RI ,
337and
338.Sx \&IR .
339.Ss \&DT
340Has no effect.
341Included for compatibility.
342.Ss \&HP
343Begin a paragraph whose initial output line is left-justified, but
344subsequent output lines are indented, with the following syntax:
345.Bd -filled -offset indent
346.Pf \. Sx \&HP
347.Op Cm width
348.Ed
349.Pp
350The
351.Cm width
352argument must conform to
353.Sx Scaling Widths .
354If specified, it's saved for later paragraph left-margins; if unspecified, the
355saved or default width is used.
356.Pp
357See also
358.Sx \&IP ,
359.Sx \&LP ,
360.Sx \&P ,
361.Sx \&PP ,
362and
363.Sx \&TP .
364.Ss \&I
365Text is rendered in italics.
366.Pp
367See also
368.Sx \&B
369and
370.Sx \&R .
371.Ss \&IB
372Text is rendered alternately in italics and bold face.
373Whitespace between arguments is omitted in output.
374.Pp
375See
376.Sx \&BI
377for an equivalent example.
378.Pp
379See also
380.Sx \&BI ,
381.Sx \&BR ,
382.Sx \&RB ,
383.Sx \&RI ,
384and
385.Sx \&IR .
386.Ss \&IP
387Begin an indented paragraph with the following syntax:
388.Bd -filled -offset indent
389.Pf \. Sx \&IP
390.Op Cm head Op Cm width
391.Ed
392.Pp
393The
394.Cm width
395argument defines the width of the left margin and is defined by
396.Sx Scaling Widths .
397It's saved for later paragraph left-margins; if unspecified, the saved or
398default width is used.
399.Pp
400The
401.Cm head
402argument is used as a leading term, flushed to the left margin.
403This is useful for bulleted paragraphs and so on.
404.Pp
405See also
406.Sx \&HP ,
407.Sx \&LP ,
408.Sx \&P ,
409.Sx \&PP ,
410and
411.Sx \&TP .
412.Ss \&IR
413Text is rendered alternately in italics and roman (the default font).
414Whitespace between arguments is omitted in output.
415.Pp
416See
417.Sx \&BI
418for an equivalent example.
419.Pp
420See also
421.Sx \&BI ,
422.Sx \&IB ,
423.Sx \&BR ,
424.Sx \&RB ,
425and
426.Sx \&RI .
427.Ss \&LP
428Begin an undecorated paragraph.
429The scope of a paragraph is closed by a subsequent paragraph,
430sub-section, section, or end of file.
431The saved paragraph left-margin width is reset to the default.
432.Pp
433See also
434.Sx \&HP ,
435.Sx \&IP ,
436.Sx \&P ,
437.Sx \&PP ,
438and
439.Sx \&TP .
440.Ss \&OP
441Optional command-line argument.
442This is a non-standard GNU extension, included only for compatibility.
443It has the following syntax:
444.Bd -filled -offset indent
445.Pf \. Sx \&OP
446.Cm key Op Cm value
447.Ed
448.Pp
449The
450.Cm key
451is usually a command-line flag and
452.Cm value
453its argument.
454.Ss \&P
455Synonym for
456.Sx \&LP .
457.Pp
458See also
459.Sx \&HP ,
460.Sx \&IP ,
461.Sx \&LP ,
462.Sx \&PP ,
463and
464.Sx \&TP .
465.Ss \&PP
466Synonym for
467.Sx \&LP .
468.Pp
469See also
470.Sx \&HP ,
471.Sx \&IP ,
472.Sx \&LP ,
473.Sx \&P ,
474and
475.Sx \&TP .
476.Ss \&R
477Text is rendered in roman (the default font).
478.Pp
479See also
480.Sx \&I
481and
482.Sx \&B .
483.Ss \&RB
484Text is rendered alternately in roman (the default font) and bold face.
485Whitespace between arguments is omitted in output.
486.Pp
487See
488.Sx \&BI
489for an equivalent example.
490.Pp
491See also
492.Sx \&BI ,
493.Sx \&IB ,
494.Sx \&BR ,
495.Sx \&RI ,
496and
497.Sx \&IR .
498.Ss \&RE
499Explicitly close out the scope of a prior
500.Sx \&RS .
501The default left margin is restored to the state of the original
502.Sx \&RS
503invocation.
504.Ss \&RI
505Text is rendered alternately in roman (the default font) and italics.
506Whitespace between arguments is omitted in output.
507.Pp
508See
509.Sx \&BI
510for an equivalent example.
511.Pp
512See also
513.Sx \&BI ,
514.Sx \&IB ,
515.Sx \&BR ,
516.Sx \&RB ,
517and
518.Sx \&IR .
519.Ss \&RS
520Temporarily reset the default left margin.
521This has the following syntax:
522.Bd -filled -offset indent
523.Pf \. Sx \&RS
524.Op Cm width
525.Ed
526.Pp
527The
528.Cm width
529argument must conform to
530.Sx Scaling Widths .
531If not specified, the saved or default width is used.
532.Pp
533See also
534.Sx \&RE .
535.Ss \&SB
536Text is rendered in small size (one point smaller than the default font)
537bold face.
538.Ss \&SH
539Begin a section.
540The scope of a section is only closed by another section or the end of
541file.
542The paragraph left-margin width is reset to the default.
543.Ss \&SM
544Text is rendered in small size (one point smaller than the default
545font).
546.Ss \&SS
547Begin a sub-section.
548The scope of a sub-section is closed by a subsequent sub-section,
549section, or end of file.
550The paragraph left-margin width is reset to the default.
551.Ss \&TH
552Sets the title of the manual page with the following syntax:
553.Bd -filled -offset indent
554.Pf \. Sx \&TH
555.Ar title section date
556.Op Ar source Op Ar volume
557.Ed
558.Pp
559Conventionally, the document
560.Ar title
561is given in all caps.
562The recommended
563.Ar date
564format is
565.Sy YYYY-MM-DD
566as specified in the ISO-8601 standard;
567if the argument does not conform, it is printed verbatim.
568If the
569.Ar date
570is empty or not specified, the current date is used.
571The optional
572.Ar source
573string specifies the organisation providing the utility.
574The
575.Ar volume
576string replaces the default rendered volume, which is dictated by the
577manual section.
578.Pp
579Examples:
580.Pp
581.Dl \&.TH CVS 5 "1992-02-12" GNU
582.Ss \&TP
583Begin a paragraph where the head, if exceeding the indentation width, is
584followed by a newline; if not, the body follows on the same line after a
585buffer to the indentation width.
586Subsequent output lines are indented.
587The syntax is as follows:
588.Bd -filled -offset indent
589.Pf \. Sx \&TP
590.Op Cm width
591.Ed
592.Pp
593The
594.Cm width
595argument must conform to
596.Sx Scaling Widths .
597If specified, it's saved for later paragraph left-margins; if
598unspecified, the saved or default width is used.
599.Pp
600See also
601.Sx \&HP ,
602.Sx \&IP ,
603.Sx \&LP ,
604.Sx \&P ,
605and
606.Sx \&PP .
607.Ss \&UC
608Sets the volume for the footer for compatibility with man pages from
609BSD releases.
610The optional first argument specifies which release it is from.
611.Ss \&br
612Breaks the current line.
613Consecutive invocations have no further effect.
614.Pp
615See also
616.Sx \&sp .
617.Ss \&fi
618End literal mode begun by
619.Sx \&nf .
620.Ss \&in
621Indent relative to the current indentation:
622.Pp
623.D1 Pf \. Sx \&in Op Cm width
624.Pp
625If
626.Cm width
627is signed, the new offset is relative.
628Otherwise, it is absolute.
629This value is reset upon the next paragraph, section, or sub-section.
630.Ss \&na
631Don't align to the right margin.
632.Ss \&nf
633Begin literal mode: all subsequent free-form lines have their end of
634line boundaries preserved.
635May be ended by
636.Sx \&fi .
637Literal mode is implicitly ended by
638.Sx \&SH
639or
640.Sx \&SS .
641.Ss \&sp
642Insert vertical spaces into output with the following syntax:
643.Bd -filled -offset indent
644.Pf \. Sx \&sp
645.Op Cm height
646.Ed
647.Pp
648Insert
649.Cm height
650spaces, which must conform to
651.Sx Scaling Widths .
652If 0, this is equivalent to the
653.Sx \&br
654macro.
655Defaults to 1, if unspecified.
656.Pp
657See also
658.Sx \&br .
659.Sh MACRO SYNTAX
660The
661.Nm
662macros are classified by scope: line scope or block scope.
663Line macros are only scoped to the current line (and, in some
664situations, the subsequent line).
665Block macros are scoped to the current line and subsequent lines until
666closed by another block macro.
667.Ss Line Macros
668Line macros are generally scoped to the current line, with the body
669consisting of zero or more arguments.
670If a macro is scoped to the next line and the line arguments are empty,
671the next line, which must be text, is used instead.
672Thus:
673.Bd -literal -offset indent
674\&.I
675foo
676.Ed
677.Pp
678is equivalent to
679.Sq \&.I foo .
680If next-line macros are invoked consecutively, only the last is used.
681If a next-line macro is followed by a non-next-line macro, an error is
682raised, except for
683.Sx \&br ,
684.Sx \&sp ,
685and
686.Sx \&na .
687.Pp
688The syntax is as follows:
689.Bd -literal -offset indent
690\&.YO \(lBbody...\(rB
691\(lBbody...\(rB
692.Ed
693.Bl -column "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX" -offset indent
694.It Em Macro Ta Em Arguments Ta Em Scope     Ta Em Notes
695.It Sx \&AT  Ta    <=1       Ta    current   Ta    \&
696.It Sx \&B   Ta    n         Ta    next-line Ta    \&
697.It Sx \&BI  Ta    n         Ta    current   Ta    \&
698.It Sx \&BR  Ta    n         Ta    current   Ta    \&
699.It Sx \&DT  Ta    0         Ta    current   Ta    \&
700.It Sx \&I   Ta    n         Ta    next-line Ta    \&
701.It Sx \&IB  Ta    n         Ta    current   Ta    \&
702.It Sx \&IR  Ta    n         Ta    current   Ta    \&
703.It Sx \&OP  Ta    0, 1      Ta    current   Ta    compat
704.It Sx \&R   Ta    n         Ta    next-line Ta    \&
705.It Sx \&RB  Ta    n         Ta    current   Ta    \&
706.It Sx \&RI  Ta    n         Ta    current   Ta    \&
707.It Sx \&SB  Ta    n         Ta    next-line Ta    \&
708.It Sx \&SM  Ta    n         Ta    next-line Ta    \&
709.It Sx \&TH  Ta    >1, <6    Ta    current   Ta    \&
710.It Sx \&UC  Ta    <=1       Ta    current   Ta    \&
711.It Sx \&br  Ta    0         Ta    current   Ta    compat
712.It Sx \&fi  Ta    0         Ta    current   Ta    compat
713.It Sx \&in  Ta    1         Ta    current   Ta    compat
714.It Sx \&na  Ta    0         Ta    current   Ta    compat
715.It Sx \&nf  Ta    0         Ta    current   Ta    compat
716.It Sx \&sp  Ta    1         Ta    current   Ta    compat
717.El
718.Pp
719Macros marked as
720.Qq compat
721are included for compatibility with the significant corpus of existing
722manuals that mix dialects of roff.
723These macros should not be used for portable
724.Nm
725manuals.
726.Ss Block Macros
727Block macros comprise a head and body.
728As with in-line macros, the head is scoped to the current line and, in
729one circumstance, the next line (the next-line stipulations as in
730.Sx Line Macros
731apply here as well).
732.Pp
733The syntax is as follows:
734.Bd -literal -offset indent
735\&.YO \(lBhead...\(rB
736\(lBhead...\(rB
737\(lBbody...\(rB
738.Ed
739.Pp
740The closure of body scope may be to the section, where a macro is closed
741by
742.Sx \&SH ;
743sub-section, closed by a section or
744.Sx \&SS ;
745part, closed by a section, sub-section, or
746.Sx \&RE ;
747or paragraph, closed by a section, sub-section, part,
748.Sx \&HP ,
749.Sx \&IP ,
750.Sx \&LP ,
751.Sx \&P ,
752.Sx \&PP ,
753or
754.Sx \&TP .
755No closure refers to an explicit block closing macro.
756.Pp
757As a rule, block macros may not be nested; thus, calling a block macro
758while another block macro scope is open, and the open scope is not
759implicitly closed, is syntactically incorrect.
760.Bl -column "MacroX" "ArgumentsX" "Head ScopeX" "sub-sectionX" "compatX" -offset indent
761.It Em Macro Ta Em Arguments Ta Em Head Scope Ta Em Body Scope  Ta Em Notes
762.It Sx \&HP  Ta    <2        Ta    current    Ta    paragraph   Ta    \&
763.It Sx \&IP  Ta    <3        Ta    current    Ta    paragraph   Ta    \&
764.It Sx \&LP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
765.It Sx \&P   Ta    0         Ta    current    Ta    paragraph   Ta    \&
766.It Sx \&PP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
767.It Sx \&RE  Ta    0         Ta    current    Ta    none        Ta    compat
768.It Sx \&RS  Ta    1         Ta    current    Ta    part        Ta    compat
769.It Sx \&SH  Ta    >0        Ta    next-line  Ta    section     Ta    \&
770.It Sx \&SS  Ta    >0        Ta    next-line  Ta    sub-section Ta    \&
771.It Sx \&TP  Ta    n         Ta    next-line  Ta    paragraph   Ta    \&
772.El
773.Pp
774Macros marked
775.Qq compat
776are as mentioned in
777.Sx Line Macros .
778.Pp
779If a block macro is next-line scoped, it may only be followed by in-line
780macros for decorating text.
781.Ss Font handling
782In
783.Nm
784documents, both
785.Sx Physical markup
786macros and
787.Xr roff 7
788.Ql \ef
789font escape sequences can be used to choose fonts.
790In text lines, the effect of manual font selection by escape sequences
791only lasts until the next macro invocation; in macro lines, it only lasts
792until the end of the macro scope.
793Note that macros like
794.Sx \&BR
795open and close a font scope for each argument.
796.Sh COMPATIBILITY
797This section documents areas of questionable portability between
798implementations of the
799.Nm
800language.
801.Pp
802.Bl -dash -compact
803.It
804Do not depend on
805.Sx \&SH
806or
807.Sx \&SS
808to close out a literal context opened with
809.Sx \&nf .
810This behaviour may not be portable.
811.It
812In quoted literals, GNU troff allowed pair-wise double-quotes to produce
813a standalone double-quote in formatted output.
814It is not known whether this behaviour is exhibited by other formatters.
815.It
816troff suppresses a newline before
817.Sq \(aq
818macro output; in mandoc, it is an alias for the standard
819.Sq \&.
820control character.
821.It
822The
823.Sq \eh
824.Pq horizontal position ,
825.Sq \ev
826.Pq vertical position ,
827.Sq \em
828.Pq text colour ,
829.Sq \eM
830.Pq text filling colour ,
831.Sq \ez
832.Pq zero-length character ,
833.Sq \ew
834.Pq string length ,
835.Sq \ek
836.Pq horizontal position marker ,
837.Sq \eo
838.Pq text overstrike ,
839and
840.Sq \es
841.Pq text size
842escape sequences are all discarded in mandoc.
843.It
844The
845.Sq \ef
846scaling unit is accepted by mandoc, but rendered as the default unit.
847.It
848The
849.Sx \&sp
850macro does not accept negative values in mandoc.
851In GNU troff, this would result in strange behaviour.
852.It
853In page header lines, GNU troff versions up to and including 1.21
854only print
855.Ar volume
856names explicitly specified in the
857.Sx \&TH
858macro; mandoc and newer groff print the default volume name
859corresponding to the
860.Ar section
861number when no
862.Ar volume
863is given, like in
864.Xr mdoc 7 .
865.El
866.Pp
867The
868.Sx OP
869macro is part of the extended
870.Nm
871macro set, and may not be portable to non-GNU troff implementations.
872.Sh SEE ALSO
873.Xr man 1 ,
874.Xr mandoc 1 ,
875.Xr eqn 7 ,
876.Xr mandoc_char 7 ,
877.Xr mdoc 7 ,
878.Xr roff 7 ,
879.Xr tbl 7
880.Sh HISTORY
881The
882.Nm
883language first appeared as a macro package for the roff typesetting
884system in
885.At v7 .
886It was later rewritten by James Clark as a macro package for groff.
887Eric S. Raymond wrote the extended
888.Nm
889macros for groff in 2007.
890The stand-alone implementation that is part of the
891.Xr mandoc 1
892utility written by Kristaps Dzonsons appeared in
893.Ox 4.6 .
894.Sh AUTHORS
895This
896.Nm
897reference was written by
898.An Kristaps Dzonsons ,
899.Mt kristaps@bsd.lv .
900.Sh CAVEATS
901Do not use this language.
902Use
903.Xr mdoc 7 ,
904instead.
905