xref: /dragonfly/contrib/mdocml/man.7 (revision 0dace59e)
1.\"	$Id: man.7,v 1.120 2013/09/16 22:58:57 schwarze Exp $
2.\"
3.\" Copyright (c) 2009, 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
4.\" Copyright (c) 2011, 2012 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: September 16 2013 $
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 PD Ta set vertical paragraph distance: Op Ar height
257.It Sx \&br Ta force output line break in text mode (no arguments)
258.It Sx \&sp Ta force vertical space: Op Ar height
259.It Sx fi , nf Ta fill mode and no-fill mode (no arguments)
260.It Sx in Ta additional indent: Op Ar width
261.El
262.Ss Physical markup
263.Bl -column "PP, LP, P" description
264.It Sx B Ta boldface font
265.It Sx I Ta italic font
266.It Sx R Ta roman (default) font
267.It Sx SB Ta small boldface font
268.It Sx SM Ta small roman font
269.It Sx BI Ta alternate between boldface and italic fonts
270.It Sx BR Ta alternate between boldface and roman fonts
271.It Sx IB Ta alternate between italic and boldface fonts
272.It Sx IR Ta alternate between italic and roman fonts
273.It Sx RB Ta alternate between roman and boldface fonts
274.It Sx RI Ta alternate between roman and italic fonts
275.El
276.Sh MACRO REFERENCE
277This section is a canonical reference to all macros, arranged
278alphabetically.
279For the scoping of individual macros, see
280.Sx MACRO SYNTAX .
281.Ss \&AT
282Sets the volume for the footer for compatibility with man pages from
283.Tn AT&T UNIX
284releases.
285The optional arguments specify which release it is from.
286.Ss \&B
287Text is rendered in bold face.
288.Pp
289See also
290.Sx \&I
291and
292.Sx \&R .
293.Ss \&BI
294Text is rendered alternately in bold face and italic.
295Thus,
296.Sq .BI this word and that
297causes
298.Sq this
299and
300.Sq and
301to render in bold face, while
302.Sq word
303and
304.Sq that
305render in italics.
306Whitespace between arguments is omitted in output.
307.Pp
308Examples:
309.Pp
310.Dl \&.BI bold italic bold italic
311.Pp
312The output of this example will be emboldened
313.Dq bold
314and italicised
315.Dq italic ,
316with spaces stripped between arguments.
317.Pp
318See also
319.Sx \&IB ,
320.Sx \&BR ,
321.Sx \&RB ,
322.Sx \&RI ,
323and
324.Sx \&IR .
325.Ss \&BR
326Text is rendered alternately in bold face and roman (the default font).
327Whitespace between arguments is omitted in output.
328.Pp
329See
330.Sx \&BI
331for an equivalent example.
332.Pp
333See also
334.Sx \&BI ,
335.Sx \&IB ,
336.Sx \&RB ,
337.Sx \&RI ,
338and
339.Sx \&IR .
340.Ss \&DT
341Has no effect.
342Included for compatibility.
343.Ss \&EE
344This is a non-standard GNU extension, included only for compatibility.
345In
346.Xr mandoc 1 ,
347it does the same as
348.Sx \&fi .
349.Ss \&EX
350This is a non-standard GNU extension, included only for compatibility.
351In
352.Xr mandoc 1 ,
353it does the same as
354.Sx \&nf .
355.Ss \&HP
356Begin a paragraph whose initial output line is left-justified, but
357subsequent output lines are indented, with the following syntax:
358.Bd -filled -offset indent
359.Pf \. Sx \&HP
360.Op Cm width
361.Ed
362.Pp
363The
364.Cm width
365argument is a
366.Xr roff 7
367scaling width.
368If specified, it's saved for later paragraph left-margins; if unspecified, the
369saved or default width is used.
370.Pp
371See also
372.Sx \&IP ,
373.Sx \&LP ,
374.Sx \&P ,
375.Sx \&PP ,
376and
377.Sx \&TP .
378.Ss \&I
379Text is rendered in italics.
380.Pp
381See also
382.Sx \&B
383and
384.Sx \&R .
385.Ss \&IB
386Text is rendered alternately in italics and bold face.
387Whitespace between arguments is omitted in output.
388.Pp
389See
390.Sx \&BI
391for an equivalent example.
392.Pp
393See also
394.Sx \&BI ,
395.Sx \&BR ,
396.Sx \&RB ,
397.Sx \&RI ,
398and
399.Sx \&IR .
400.Ss \&IP
401Begin an indented paragraph with the following syntax:
402.Bd -filled -offset indent
403.Pf \. Sx \&IP
404.Op Cm head Op Cm width
405.Ed
406.Pp
407The
408.Cm width
409argument is a
410.Xr roff 7
411scaling width defining the left margin.
412It's saved for later paragraph left-margins; if unspecified, the saved or
413default width is used.
414.Pp
415The
416.Cm head
417argument is used as a leading term, flushed to the left margin.
418This is useful for bulleted paragraphs and so on.
419.Pp
420See also
421.Sx \&HP ,
422.Sx \&LP ,
423.Sx \&P ,
424.Sx \&PP ,
425and
426.Sx \&TP .
427.Ss \&IR
428Text is rendered alternately in italics and roman (the default font).
429Whitespace between arguments is omitted in output.
430.Pp
431See
432.Sx \&BI
433for an equivalent example.
434.Pp
435See also
436.Sx \&BI ,
437.Sx \&IB ,
438.Sx \&BR ,
439.Sx \&RB ,
440and
441.Sx \&RI .
442.Ss \&LP
443Begin an undecorated paragraph.
444The scope of a paragraph is closed by a subsequent paragraph,
445sub-section, section, or end of file.
446The saved paragraph left-margin width is reset to the default.
447.Pp
448See also
449.Sx \&HP ,
450.Sx \&IP ,
451.Sx \&P ,
452.Sx \&PP ,
453and
454.Sx \&TP .
455.Ss \&OP
456Optional command-line argument.
457This is a non-standard GNU extension, included only for compatibility.
458It has the following syntax:
459.Bd -filled -offset indent
460.Pf \. Sx \&OP
461.Cm key Op Cm value
462.Ed
463.Pp
464The
465.Cm key
466is usually a command-line flag and
467.Cm value
468its argument.
469.Ss \&P
470Synonym for
471.Sx \&LP .
472.Pp
473See also
474.Sx \&HP ,
475.Sx \&IP ,
476.Sx \&LP ,
477.Sx \&PP ,
478and
479.Sx \&TP .
480.Ss \&PD
481Specify the vertical space to be inserted before each new paragraph.
482.br
483The syntax is as follows:
484.Bd -filled -offset indent
485.Pf \. Sx \&PD
486.Op Cm height
487.Ed
488.Pp
489The
490.Cm height
491argument is a
492.Xr roff 7
493scaling width.
494It defaults to
495.Cm 1v .
496If the unit is omitted,
497.Cm v
498is assumed.
499.Pp
500This macro affects the spacing before any subsequent instances of
501.Sx \&HP ,
502.Sx \&IP ,
503.Sx \&LP ,
504.Sx \&P ,
505.Sx \&PP ,
506.Sx \&SH ,
507.Sx \&SS ,
508and
509.Sx \&TP .
510.Ss \&PP
511Synonym for
512.Sx \&LP .
513.Pp
514See also
515.Sx \&HP ,
516.Sx \&IP ,
517.Sx \&LP ,
518.Sx \&P ,
519and
520.Sx \&TP .
521.Ss \&R
522Text is rendered in roman (the default font).
523.Pp
524See also
525.Sx \&I
526and
527.Sx \&B .
528.Ss \&RB
529Text is rendered alternately in roman (the default font) and bold face.
530Whitespace between arguments is omitted in output.
531.Pp
532See
533.Sx \&BI
534for an equivalent example.
535.Pp
536See also
537.Sx \&BI ,
538.Sx \&IB ,
539.Sx \&BR ,
540.Sx \&RI ,
541and
542.Sx \&IR .
543.Ss \&RE
544Explicitly close out the scope of a prior
545.Sx \&RS .
546The default left margin is restored to the state of the original
547.Sx \&RS
548invocation.
549.Ss \&RI
550Text is rendered alternately in roman (the default font) and italics.
551Whitespace between arguments is omitted in output.
552.Pp
553See
554.Sx \&BI
555for an equivalent example.
556.Pp
557See also
558.Sx \&BI ,
559.Sx \&IB ,
560.Sx \&BR ,
561.Sx \&RB ,
562and
563.Sx \&IR .
564.Ss \&RS
565Temporarily reset the default left margin.
566This has the following syntax:
567.Bd -filled -offset indent
568.Pf \. Sx \&RS
569.Op Cm width
570.Ed
571.Pp
572The
573.Cm width
574argument is a
575.Xr roff 7
576scaling width.
577If not specified, the saved or default width is used.
578.Pp
579See also
580.Sx \&RE .
581.Ss \&SB
582Text is rendered in small size (one point smaller than the default font)
583bold face.
584.Ss \&SH
585Begin a section.
586The scope of a section is only closed by another section or the end of
587file.
588The paragraph left-margin width is reset to the default.
589.Ss \&SM
590Text is rendered in small size (one point smaller than the default
591font).
592.Ss \&SS
593Begin a sub-section.
594The scope of a sub-section is closed by a subsequent sub-section,
595section, or end of file.
596The paragraph left-margin width is reset to the default.
597.Ss \&TH
598Sets the title of the manual page with the following syntax:
599.Bd -filled -offset indent
600.Pf \. Sx \&TH
601.Ar title section date
602.Op Ar source Op Ar volume
603.Ed
604.Pp
605Conventionally, the document
606.Ar title
607is given in all caps.
608The recommended
609.Ar date
610format is
611.Sy YYYY-MM-DD
612as specified in the ISO-8601 standard;
613if the argument does not conform, it is printed verbatim.
614If the
615.Ar date
616is empty or not specified, the current date is used.
617The optional
618.Ar source
619string specifies the organisation providing the utility.
620The
621.Ar volume
622string replaces the default rendered volume, which is dictated by the
623manual section.
624.Pp
625Examples:
626.Pp
627.Dl \&.TH CVS 5 "1992-02-12" GNU
628.Ss \&TP
629Begin a paragraph where the head, if exceeding the indentation width, is
630followed by a newline; if not, the body follows on the same line after a
631buffer to the indentation width.
632Subsequent output lines are indented.
633The syntax is as follows:
634.Bd -filled -offset indent
635.Pf \. Sx \&TP
636.Op Cm width
637.Ed
638.Pp
639The
640.Cm width
641argument is a
642.Xr roff 7
643scaling width.
644If specified, it's saved for later paragraph left-margins; if
645unspecified, the saved or default width is used.
646.Pp
647See also
648.Sx \&HP ,
649.Sx \&IP ,
650.Sx \&LP ,
651.Sx \&P ,
652and
653.Sx \&PP .
654.Ss \&UC
655Sets the volume for the footer for compatibility with man pages from
656.Bx
657releases.
658The optional first argument specifies which release it is from.
659.Ss \&br
660Breaks the current line.
661Consecutive invocations have no further effect.
662.Pp
663See also
664.Sx \&sp .
665.Ss \&fi
666End literal mode begun by
667.Sx \&nf .
668.Ss \&ft
669Change the current font mode.
670See
671.Sx Text Decoration
672for a listing of available font modes.
673.Ss \&in
674Indent relative to the current indentation:
675.Pp
676.D1 Pf \. Sx \&in Op Cm width
677.Pp
678If
679.Cm width
680is signed, the new offset is relative.
681Otherwise, it is absolute.
682This value is reset upon the next paragraph, section, or sub-section.
683.Ss \&na
684Don't align to the right margin.
685.Ss \&nf
686Begin literal mode: all subsequent free-form lines have their end of
687line boundaries preserved.
688May be ended by
689.Sx \&fi .
690Literal mode is implicitly ended by
691.Sx \&SH
692or
693.Sx \&SS .
694.Ss \&sp
695Insert vertical spaces into output with the following syntax:
696.Bd -filled -offset indent
697.Pf \. Sx \&sp
698.Op Cm height
699.Ed
700.Pp
701The
702.Cm height
703argument is a scaling width as described in
704.Xr roff 7 .
705If 0, this is equivalent to the
706.Sx \&br
707macro.
708Defaults to 1, if unspecified.
709.Pp
710See also
711.Sx \&br .
712.Sh MACRO SYNTAX
713The
714.Nm
715macros are classified by scope: line scope or block scope.
716Line macros are only scoped to the current line (and, in some
717situations, the subsequent line).
718Block macros are scoped to the current line and subsequent lines until
719closed by another block macro.
720.Ss Line Macros
721Line macros are generally scoped to the current line, with the body
722consisting of zero or more arguments.
723If a macro is scoped to the next line and the line arguments are empty,
724the next line, which must be text, is used instead.
725Thus:
726.Bd -literal -offset indent
727\&.I
728foo
729.Ed
730.Pp
731is equivalent to
732.Sq \&.I foo .
733If next-line macros are invoked consecutively, only the last is used.
734If a next-line macro is followed by a non-next-line macro, an error is
735raised, except for
736.Sx \&br ,
737.Sx \&sp ,
738and
739.Sx \&na .
740.Pp
741The syntax is as follows:
742.Bd -literal -offset indent
743\&.YO \(lBbody...\(rB
744\(lBbody...\(rB
745.Ed
746.Bl -column "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX" -offset indent
747.It Em Macro Ta Em Arguments Ta Em Scope     Ta Em Notes
748.It Sx \&AT  Ta    <=1       Ta    current   Ta    \&
749.It Sx \&B   Ta    n         Ta    next-line Ta    \&
750.It Sx \&BI  Ta    n         Ta    current   Ta    \&
751.It Sx \&BR  Ta    n         Ta    current   Ta    \&
752.It Sx \&DT  Ta    0         Ta    current   Ta    \&
753.It Sx \&I   Ta    n         Ta    next-line Ta    \&
754.It Sx \&IB  Ta    n         Ta    current   Ta    \&
755.It Sx \&IR  Ta    n         Ta    current   Ta    \&
756.It Sx \&OP  Ta    0, 1      Ta    current   Ta    compat
757.It Sx \&R   Ta    n         Ta    next-line Ta    \&
758.It Sx \&RB  Ta    n         Ta    current   Ta    \&
759.It Sx \&RI  Ta    n         Ta    current   Ta    \&
760.It Sx \&SB  Ta    n         Ta    next-line Ta    \&
761.It Sx \&SM  Ta    n         Ta    next-line Ta    \&
762.It Sx \&TH  Ta    >1, <6    Ta    current   Ta    \&
763.It Sx \&UC  Ta    <=1       Ta    current   Ta    \&
764.It Sx \&br  Ta    0         Ta    current   Ta    compat
765.It Sx \&fi  Ta    0         Ta    current   Ta    compat
766.It Sx \&ft  Ta    1         Ta    current   Ta    compat
767.It Sx \&in  Ta    1         Ta    current   Ta    compat
768.It Sx \&na  Ta    0         Ta    current   Ta    compat
769.It Sx \&nf  Ta    0         Ta    current   Ta    compat
770.It Sx \&sp  Ta    1         Ta    current   Ta    compat
771.El
772.Pp
773Macros marked as
774.Qq compat
775are included for compatibility with the significant corpus of existing
776manuals that mix dialects of roff.
777These macros should not be used for portable
778.Nm
779manuals.
780.Ss Block Macros
781Block macros comprise a head and body.
782As with in-line macros, the head is scoped to the current line and, in
783one circumstance, the next line (the next-line stipulations as in
784.Sx Line Macros
785apply here as well).
786.Pp
787The syntax is as follows:
788.Bd -literal -offset indent
789\&.YO \(lBhead...\(rB
790\(lBhead...\(rB
791\(lBbody...\(rB
792.Ed
793.Pp
794The closure of body scope may be to the section, where a macro is closed
795by
796.Sx \&SH ;
797sub-section, closed by a section or
798.Sx \&SS ;
799part, closed by a section, sub-section, or
800.Sx \&RE ;
801or paragraph, closed by a section, sub-section, part,
802.Sx \&HP ,
803.Sx \&IP ,
804.Sx \&LP ,
805.Sx \&P ,
806.Sx \&PP ,
807or
808.Sx \&TP .
809No closure refers to an explicit block closing macro.
810.Pp
811As a rule, block macros may not be nested; thus, calling a block macro
812while another block macro scope is open, and the open scope is not
813implicitly closed, is syntactically incorrect.
814.Bl -column "MacroX" "ArgumentsX" "Head ScopeX" "sub-sectionX" "compatX" -offset indent
815.It Em Macro Ta Em Arguments Ta Em Head Scope Ta Em Body Scope  Ta Em Notes
816.It Sx \&HP  Ta    <2        Ta    current    Ta    paragraph   Ta    \&
817.It Sx \&IP  Ta    <3        Ta    current    Ta    paragraph   Ta    \&
818.It Sx \&LP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
819.It Sx \&P   Ta    0         Ta    current    Ta    paragraph   Ta    \&
820.It Sx \&PP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
821.It Sx \&RE  Ta    0         Ta    current    Ta    none        Ta    compat
822.It Sx \&RS  Ta    1         Ta    current    Ta    part        Ta    compat
823.It Sx \&SH  Ta    >0        Ta    next-line  Ta    section     Ta    \&
824.It Sx \&SS  Ta    >0        Ta    next-line  Ta    sub-section Ta    \&
825.It Sx \&TP  Ta    n         Ta    next-line  Ta    paragraph   Ta    \&
826.El
827.Pp
828Macros marked
829.Qq compat
830are as mentioned in
831.Sx Line Macros .
832.Pp
833If a block macro is next-line scoped, it may only be followed by in-line
834macros for decorating text.
835.Ss Font handling
836In
837.Nm
838documents, both
839.Sx Physical markup
840macros and
841.Xr roff 7
842.Ql \ef
843font escape sequences can be used to choose fonts.
844In text lines, the effect of manual font selection by escape sequences
845only lasts until the next macro invocation; in macro lines, it only lasts
846until the end of the macro scope.
847Note that macros like
848.Sx \&BR
849open and close a font scope for each argument.
850.Sh COMPATIBILITY
851This section documents areas of questionable portability between
852implementations of the
853.Nm
854language.
855.Pp
856.Bl -dash -compact
857.It
858Do not depend on
859.Sx \&SH
860or
861.Sx \&SS
862to close out a literal context opened with
863.Sx \&nf .
864This behaviour may not be portable.
865.It
866In quoted literals, GNU troff allowed pair-wise double-quotes to produce
867a standalone double-quote in formatted output.
868It is not known whether this behaviour is exhibited by other formatters.
869.It
870troff suppresses a newline before
871.Sq \(aq
872macro output; in mandoc, it is an alias for the standard
873.Sq \&.
874control character.
875.It
876The
877.Sq \eh
878.Pq horizontal position ,
879.Sq \ev
880.Pq vertical position ,
881.Sq \em
882.Pq text colour ,
883.Sq \eM
884.Pq text filling colour ,
885.Sq \ez
886.Pq zero-length character ,
887.Sq \ew
888.Pq string length ,
889.Sq \ek
890.Pq horizontal position marker ,
891.Sq \eo
892.Pq text overstrike ,
893and
894.Sq \es
895.Pq text size
896escape sequences are all discarded in mandoc.
897.It
898The
899.Sq \ef
900scaling unit is accepted by mandoc, but rendered as the default unit.
901.It
902The
903.Sx \&sp
904macro does not accept negative values in mandoc.
905In GNU troff, this would result in strange behaviour.
906.It
907In page header lines, GNU troff versions up to and including 1.21
908only print
909.Ar volume
910names explicitly specified in the
911.Sx \&TH
912macro; mandoc and newer groff print the default volume name
913corresponding to the
914.Ar section
915number when no
916.Ar volume
917is given, like in
918.Xr mdoc 7 .
919.El
920.Pp
921The
922.Sx OP
923macro is part of the extended
924.Nm
925macro set, and may not be portable to non-GNU troff implementations.
926.Sh SEE ALSO
927.Xr man 1 ,
928.Xr mandoc 1 ,
929.Xr eqn 7 ,
930.Xr mandoc_char 7 ,
931.Xr mdoc 7 ,
932.Xr roff 7 ,
933.Xr tbl 7
934.Sh HISTORY
935The
936.Nm
937language first appeared as a macro package for the roff typesetting
938system in
939.At v7 .
940It was later rewritten by James Clark as a macro package for groff.
941Eric S. Raymond wrote the extended
942.Nm
943macros for groff in 2007.
944The stand-alone implementation that is part of the
945.Xr mandoc 1
946utility written by Kristaps Dzonsons appeared in
947.Ox 4.6 .
948.Sh AUTHORS
949This
950.Nm
951reference was written by
952.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .
953.Sh CAVEATS
954Do not use this language.
955Use
956.Xr mdoc 7 ,
957instead.
958