1.\" $OpenBSD: man.7,v 1.13 2011/01/09 15:24:57 schwarze Exp $ 2.\" 3.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: January 9 2011 $ 18.Dt MAN 7 19.Os 20.Sh NAME 21.Nm man 22.Nd man language reference 23.Sh DESCRIPTION 24The 25.Nm man 26language was historically used to format 27.Ux 28manuals. 29This reference document describes its syntax, structure, and usage. 30.Pp 31.Bf -emphasis 32Do not use 33.Nm 34to write your manuals. 35.Ef 36Use the 37.Xr mdoc 7 38language, instead. 39.Pp 40A 41.Nm 42document follows simple rules: lines beginning with the control 43character 44.Sq \&. 45are parsed for macros. 46Other lines are interpreted within the scope of 47prior macros: 48.Bd -literal -offset indent 49\&.SH Macro lines change control state. 50Other lines are interpreted within the current state. 51.Ed 52.Sh INPUT ENCODING 53.Nm 54documents may contain only graphable 7-bit ASCII characters, the 55space character, and the tab character. 56All manuals must have 57.Ux 58line termination. 59.Pp 60Blank lines are acceptable; where found, the output will assert a 61vertical space. 62.Ss Comments 63Text following a 64.Sq \e\*q , 65whether in a macro or free-form text line, is ignored to the end of 66line. 67A macro line with only a control character and comment escape, 68.Sq \&.\e\*q , 69is also ignored. 70Macro lines with only a control character and optionally whitespace are 71stripped from input. 72.Ss Special Characters 73Special characters may occur in both macro and free-form lines. 74Sequences begin with the escape character 75.Sq \e 76followed by either an open-parenthesis 77.Sq \&( 78for two-character sequences; an open-bracket 79.Sq \&[ 80for n-character sequences (terminated at a close-bracket 81.Sq \&] ) ; 82or a single one-character sequence. 83See 84.Xr mandoc_char 7 85for a complete list. 86Examples include 87.Sq \e(em 88.Pq em-dash 89and 90.Sq \ee 91.Pq back-slash . 92.Ss Text Decoration 93Terms may be text-decorated using the 94.Sq \ef 95escape followed by an indicator: B (bold), I (italic), R (Roman), or P 96(revert to previous mode): 97.Pp 98.D1 \efBbold\efR \efIitalic\efP 99.Pp 100A numerical representation 3, 2, or 1 (bold, italic, and Roman, 101respectively) may be used instead. 102A text decoration is only valid, if specified in free-form text, until 103the next macro invocation; if specified within a macro, it's only valid 104until the macro closes scope. 105Note that macros like 106.Sx \&BR 107open and close a font scope with each argument. 108.Pp 109The 110.Sq \ef 111attribute is forgotten when entering or exiting a macro block. 112.Ss Whitespace 113Whitespace consists of the space character. 114In free-form lines, whitespace is preserved within a line; unescaped 115trailing spaces are stripped from input (unless in a literal context). 116Blank free-form lines, which may include spaces, are permitted and 117rendered as an empty line. 118.Pp 119In macro lines, whitespace delimits arguments and is discarded. 120If arguments are quoted, whitespace within the quotes is retained. 121.Ss Dates 122The 123.Sx \&TH 124macro is the only 125.Nm 126macro that requires a date. 127The form for this date is the ISO-8601 128standard 129.Cm YYYY-MM-DD . 130.Ss Scaling Widths 131Many macros support scaled widths for their arguments, such as 132stipulating a two-inch paragraph indentation with the following: 133.Bd -literal -offset indent 134\&.HP 2i 135.Ed 136.Pp 137The syntax for scaled widths is 138.Sq Li [+-]?[0-9]*.[0-9]*[:unit:]? , 139where a decimal must be preceded or proceeded by at least one digit. 140Negative numbers, while accepted, are truncated to zero. 141The following scaling units are accepted: 142.Pp 143.Bl -tag -width Ds -offset indent -compact 144.It c 145centimetre 146.It i 147inch 148.It P 149pica (~1/6 inch) 150.It p 151point (~1/72 inch) 152.It f 153synonym for 154.Sq u 155.It v 156default vertical span 157.It m 158width of rendered 159.Sq m 160.Pq em 161character 162.It n 163width of rendered 164.Sq n 165.Pq en 166character 167.It u 168default horizontal span 169.It M 170mini-em (~1/100 em) 171.El 172.Pp 173Using anything other than 174.Sq m , 175.Sq n , 176.Sq u , 177or 178.Sq v 179is necessarily non-portable across output media. 180.Pp 181If a scaling unit is not provided, the numerical value is interpreted 182under the default rules of 183.Sq v 184for vertical spaces and 185.Sq u 186for horizontal ones. 187.Em Note : 188this differs from 189.Xr mdoc 7 , 190which, if a unit is not provided, will instead interpret the string as 191literal text. 192.Ss Sentence Spacing 193When composing a manual, make sure that sentences end at the end of 194a line. 195By doing so, front-ends will be able to apply the proper amount of 196spacing after the end of sentence (unescaped) period, exclamation mark, 197or question mark followed by zero or more non-sentence closing 198delimiters 199.Po 200.Sq \&) , 201.Sq \&] , 202.Sq \&' , 203.Sq \&" 204.Pc . 205.Sh MANUAL STRUCTURE 206Each 207.Nm 208document must contain the 209.Sx \&TH 210macro describing the document's section and title. 211It may occur anywhere in the document, although conventionally it 212appears as the first macro. 213.Pp 214Beyond 215.Sx \&TH , 216at least one macro or text node must appear in the document. 217Documents are generally structured as follows: 218.Bd -literal -offset indent 219\&.TH FOO 1 2009-10-10 220\&.SH NAME 221\efBfoo\efR \e(en a description goes here 222\&.\e\*q .SH LIBRARY 223\&.\e\*q For sections 2 & 3 only. 224\&.\e\*q Not used in OpenBSD. 225\&.SH SYNOPSIS 226\efBfoo\efR [\efB\e-options\efR] arguments... 227\&.SH DESCRIPTION 228The \efBfoo\efR utility processes files... 229\&.\e\*q .SH IMPLEMENTATION NOTES 230\&.\e\*q Not used in OpenBSD. 231\&.\e\*q .SH RETURN VALUES 232\&.\e\*q For sections 2, 3, & 9 only. 233\&.\e\*q .SH ENVIRONMENT 234\&.\e\*q For sections 1, 6, 7, & 8 only. 235\&.\e\*q .SH FILES 236\&.\e\*q .SH EXIT STATUS 237\&.\e\*q For sections 1, 6, & 8 only. 238\&.\e\*q .SH EXAMPLES 239\&.\e\*q .SH DIAGNOSTICS 240\&.\e\*q For sections 1, 4, 6, 7, & 8 only. 241\&.\e\*q .SH ERRORS 242\&.\e\*q For sections 2, 3, & 9 only. 243\&.\e\*q .SH SEE ALSO 244\&.\e\*q .BR foo ( 1 ) 245\&.\e\*q .SH STANDARDS 246\&.\e\*q .SH HISTORY 247\&.\e\*q .SH AUTHORS 248\&.\e\*q .SH CAVEATS 249\&.\e\*q .SH BUGS 250\&.\e\*q .SH SECURITY CONSIDERATIONS 251\&.\e\*q Not used in OpenBSD. 252.Ed 253.Pp 254The sections in a 255.Nm 256document are conventionally ordered as they appear above. 257Sections should be composed as follows: 258.Bl -ohang -offset indent 259.It Em NAME 260The name(s) and a short description of the documented material. 261The syntax for this is generally as follows: 262.Pp 263.D1 \efBname\efR \e(en description 264.It Em LIBRARY 265The name of the library containing the documented material, which is 266assumed to be a function in a section 2 or 3 manual. 267For functions in the C library, this may be as follows: 268.Pp 269.D1 Standard C Library (libc, -lc) 270.It Em SYNOPSIS 271Documents the utility invocation syntax, function call syntax, or device 272configuration. 273.Pp 274For the first, utilities (sections 1, 6, and 8), this is 275generally structured as follows: 276.Pp 277.D1 \efBname\efR [-\efBab\efR] [-\efBc\efR\efIarg\efR] \efBpath\efR... 278.Pp 279For the second, function calls (sections 2, 3, 9): 280.Pp 281.D1 \&.B char *name(char *\efIarg\efR); 282.Pp 283And for the third, configurations (section 4): 284.Pp 285.D1 \&.B name* at cardbus ? function ? 286.Pp 287Manuals not in these sections generally don't need a 288.Em SYNOPSIS . 289.It Em DESCRIPTION 290This expands upon the brief, one-line description in 291.Em NAME . 292It usually contains a break-down of the options (if documenting a 293command). 294.It Em IMPLEMENTATION NOTES 295Implementation-specific notes should be kept here. 296This is useful when implementing standard functions that may have side 297effects or notable algorithmic implications. 298.It Em RETURN VALUES 299This section documents the return values of functions in sections 2, 3, and 9. 300.It Em ENVIRONMENT 301Documents any usages of environment variables, e.g., 302.Xr environ 7 . 303.It Em FILES 304Documents files used. 305It's helpful to document both the file name and a short description of how 306the file is used (created, modified, etc.). 307.It Em EXIT STATUS 308This section documents the command exit status for 309section 1, 6, and 8 utilities. 310Historically, this information was described in 311.Em DIAGNOSTICS , 312a practise that is now discouraged. 313.It Em EXAMPLES 314Example usages. 315This often contains snippets of well-formed, 316well-tested invocations. 317Make sure that examples work properly! 318.It Em DIAGNOSTICS 319Documents error conditions. 320This is most useful in section 4 manuals. 321Historically, this section was used in place of 322.Em EXIT STATUS 323for manuals in sections 1, 6, and 8; however, this practise is 324discouraged. 325.It Em ERRORS 326Documents error handling in sections 2, 3, and 9. 327.It Em SEE ALSO 328References other manuals with related topics. 329This section should exist for most manuals. 330.Pp 331.D1 \&.BR bar \&( 1 \&), 332.Pp 333Cross-references should conventionally be ordered 334first by section, then alphabetically. 335.It Em STANDARDS 336References any standards implemented or used, such as 337.Pp 338.D1 IEEE Std 1003.2 (\e(lqPOSIX.2\e(rq) 339.Pp 340If not adhering to any standards, the 341.Em HISTORY 342section should be used. 343.It Em HISTORY 344A brief history of the subject, including where support first appeared. 345.It Em AUTHORS 346Credits to the person or persons who wrote the code and/or documentation. 347Authors should generally be noted by both name and email address. 348.It Em CAVEATS 349Common misuses and misunderstandings should be explained 350in this section. 351.It Em BUGS 352Known bugs, limitations, and work-arounds should be described 353in this section. 354.It Em SECURITY CONSIDERATIONS 355Documents any security precautions that operators should consider. 356.El 357.Sh MACRO SYNTAX 358Macros are one to three characters in length and begin with a 359control character, 360.Sq \&. , 361at the beginning of the line. 362The 363.Sq \(aq 364macro control character is also accepted. 365An arbitrary amount of whitespace (spaces or tabs) may sit between the 366control character and the macro name. 367Thus, the following are equivalent: 368.Bd -literal -offset indent 369\&.PP 370\&.\ \ \ PP 371.Ed 372.Pp 373The 374.Nm 375macros are classified by scope: line scope or block scope. 376Line macros are only scoped to the current line (and, in some 377situations, the subsequent line). 378Block macros are scoped to the current line and subsequent lines until 379closed by another block macro. 380.Ss Line Macros 381Line macros are generally scoped to the current line, with the body 382consisting of zero or more arguments. 383If a macro is scoped to the next line and the line arguments are empty, 384the next line, which must be text, is used instead. 385Thus: 386.Bd -literal -offset indent 387\&.I 388foo 389.Ed 390.Pp 391is equivalent to 392.Sq \&.I foo . 393If next-line macros are invoked consecutively, only the last is used. 394If a next-line macro is followed by a non-next-line macro, an error is 395raised, except for 396.Sx \&br , 397.Sx \&sp , 398and 399.Sx \&na . 400.Pp 401The syntax is as follows: 402.Bd -literal -offset indent 403\&.YO \(lBbody...\(rB 404\(lBbody...\(rB 405.Ed 406.Pp 407.Bl -column -compact -offset indent "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX" 408.It Em Macro Ta Em Arguments Ta Em Scope Ta Em Notes 409.It Sx \&AT Ta <=1 Ta current Ta \& 410.It Sx \&B Ta n Ta next-line Ta \& 411.It Sx \&BI Ta n Ta current Ta \& 412.It Sx \&BR Ta n Ta current Ta \& 413.It Sx \&DT Ta 0 Ta current Ta \& 414.It Sx \&I Ta n Ta next-line Ta \& 415.It Sx \&IB Ta n Ta current Ta \& 416.It Sx \&IR Ta n Ta current Ta \& 417.It Sx \&R Ta n Ta next-line Ta \& 418.It Sx \&RB Ta n Ta current Ta \& 419.It Sx \&RI Ta n Ta current Ta \& 420.It Sx \&SB Ta n Ta next-line Ta \& 421.It Sx \&SM Ta n Ta next-line Ta \& 422.It Sx \&TH Ta >1, <6 Ta current Ta \& 423.It Sx \&UC Ta <=1 Ta current Ta \& 424.It Sx \&br Ta 0 Ta current Ta compat 425.It Sx \&fi Ta 0 Ta current Ta compat 426.It Sx \&in Ta 1 Ta current Ta compat 427.It Sx \&na Ta 0 Ta current Ta compat 428.It Sx \&nf Ta 0 Ta current Ta compat 429.It Sx \&sp Ta 1 Ta current Ta compat 430.El 431.Pp 432Macros marked as 433.Qq compat 434are included for compatibility with the significant corpus of existing 435manuals that mix dialects of roff. 436These macros should not be used for portable 437.Nm 438manuals. 439.Ss Block Macros 440Block macros comprise a head and body. 441As with in-line macros, the head is scoped to the current line and, in 442one circumstance, the next line (the next-line stipulations as in 443.Sx Line Macros 444apply here as well). 445.Pp 446The syntax is as follows: 447.Bd -literal -offset indent 448\&.YO \(lBhead...\(rB 449\(lBhead...\(rB 450\(lBbody...\(rB 451.Ed 452.Pp 453The closure of body scope may be to the section, where a macro is closed 454by 455.Sx \&SH ; 456sub-section, closed by a section or 457.Sx \&SS ; 458part, closed by a section, sub-section, or 459.Sx \&RE ; 460or paragraph, closed by a section, sub-section, part, 461.Sx \&HP , 462.Sx \&IP , 463.Sx \&LP , 464.Sx \&P , 465.Sx \&PP , 466or 467.Sx \&TP . 468No closure refers to an explicit block closing macro. 469.Pp 470As a rule, block macros may not be nested; thus, calling a block macro 471while another block macro scope is open, and the open scope is not 472implicitly closed, is syntactically incorrect. 473.Pp 474.Bl -column -compact -offset indent "MacroX" "ArgumentsX" "Head ScopeX" "sub-sectionX" "compatX" 475.It Em Macro Ta Em Arguments Ta Em Head Scope Ta Em Body Scope Ta Em Notes 476.It Sx \&HP Ta <2 Ta current Ta paragraph Ta \& 477.It Sx \&IP Ta <3 Ta current Ta paragraph Ta \& 478.It Sx \&LP Ta 0 Ta current Ta paragraph Ta \& 479.It Sx \&P Ta 0 Ta current Ta paragraph Ta \& 480.It Sx \&PP Ta 0 Ta current Ta paragraph Ta \& 481.It Sx \&RE Ta 0 Ta current Ta none Ta compat 482.It Sx \&RS Ta 1 Ta current Ta part Ta compat 483.It Sx \&SH Ta >0 Ta next-line Ta section Ta \& 484.It Sx \&SS Ta >0 Ta next-line Ta sub-section Ta \& 485.It Sx \&TP Ta n Ta next-line Ta paragraph Ta \& 486.El 487.Pp 488Macros marked 489.Qq compat 490are as mentioned in 491.Sx Line Macros . 492.Pp 493If a block macro is next-line scoped, it may only be followed by in-line 494macros for decorating text. 495.Sh REFERENCE 496This section is a canonical reference to all macros, arranged 497alphabetically. 498For the scoping of individual macros, see 499.Sx MACRO SYNTAX . 500.Ss \&AT 501Sets the volume for the footer for compatibility with man pages from 502.Tn AT&T UNIX 503releases. 504The optional arguments specify which release it is from. 505.Ss \&B 506Text is rendered in bold face. 507.Pp 508See also 509.Sx \&I 510and 511.Sx \&R . 512.Ss \&BI 513Text is rendered alternately in bold face and italic. 514Thus, 515.Sq .BI this word and that 516causes 517.Sq this 518and 519.Sq and 520to render in bold face, while 521.Sq word 522and 523.Sq that 524render in italics. 525Whitespace between arguments is omitted in output. 526.Pp 527Examples: 528.Pp 529.Dl \&.BI bold italic bold italic 530.Pp 531The output of this example will be emboldened 532.Dq bold 533and italicised 534.Dq italic , 535with spaces stripped between arguments. 536.Pp 537See also 538.Sx \&IB , 539.Sx \&BR , 540.Sx \&RB , 541.Sx \&RI , 542and 543.Sx \&IR . 544.Ss \&BR 545Text is rendered alternately in bold face and roman (the default font). 546Whitespace between arguments is omitted in output. 547.Pp 548See 549.Sx \&BI 550for an equivalent example. 551.Pp 552See also 553.Sx \&BI , 554.Sx \&IB , 555.Sx \&RB , 556.Sx \&RI , 557and 558.Sx \&IR . 559.Ss \&DT 560Has no effect. 561Included for compatibility. 562.Ss \&HP 563Begin a paragraph whose initial output line is left-justified, but 564subsequent output lines are indented, with the following syntax: 565.Bd -filled -offset indent 566.Pf \. Sx \&HP 567.Op Cm width 568.Ed 569.Pp 570The 571.Cm width 572argument must conform to 573.Sx Scaling Widths . 574If specified, it's saved for later paragraph left-margins; if unspecified, the 575saved or default width is used. 576.Pp 577See also 578.Sx \&IP , 579.Sx \&LP , 580.Sx \&P , 581.Sx \&PP , 582and 583.Sx \&TP . 584.Ss \&I 585Text is rendered in italics. 586.Pp 587See also 588.Sx \&B 589and 590.Sx \&R . 591.Ss \&IB 592Text is rendered alternately in italics and bold face. 593Whitespace between arguments is omitted in output. 594.Pp 595See 596.Sx \&BI 597for an equivalent example. 598.Pp 599See also 600.Sx \&BI , 601.Sx \&BR , 602.Sx \&RB , 603.Sx \&RI , 604and 605.Sx \&IR . 606.Ss \&IP 607Begin an indented paragraph with the following syntax: 608.Bd -filled -offset indent 609.Pf \. Sx \&IP 610.Op Cm head Op Cm width 611.Ed 612.Pp 613The 614.Cm width 615argument defines the width of the left margin and is defined by 616.Sx Scaling Widths . 617It's saved for later paragraph left-margins; if unspecified, the saved or 618default width is used. 619.Pp 620The 621.Cm head 622argument is used as a leading term, flushed to the left margin. 623This is useful for bulleted paragraphs and so on. 624.Pp 625See also 626.Sx \&HP , 627.Sx \&LP , 628.Sx \&P , 629.Sx \&PP , 630and 631.Sx \&TP . 632.Ss \&IR 633Text is rendered alternately in italics and roman (the default font). 634Whitespace between arguments is omitted in output. 635.Pp 636See 637.Sx \&BI 638for an equivalent example. 639.Pp 640See also 641.Sx \&BI , 642.Sx \&IB , 643.Sx \&BR , 644.Sx \&RB , 645and 646.Sx \&RI . 647.Ss \&LP 648Begin an undecorated paragraph. 649The scope of a paragraph is closed by a subsequent paragraph, 650sub-section, section, or end of file. 651The saved paragraph left-margin width is reset to the default. 652.Pp 653See also 654.Sx \&HP , 655.Sx \&IP , 656.Sx \&P , 657.Sx \&PP , 658and 659.Sx \&TP . 660.Ss \&P 661Synonym for 662.Sx \&LP . 663.Pp 664See also 665.Sx \&HP , 666.Sx \&IP , 667.Sx \&LP , 668.Sx \&PP , 669and 670.Sx \&TP . 671.Ss \&PP 672Synonym for 673.Sx \&LP . 674.Pp 675See also 676.Sx \&HP , 677.Sx \&IP , 678.Sx \&LP , 679.Sx \&P , 680and 681.Sx \&TP . 682.Ss \&R 683Text is rendered in roman (the default font). 684.Pp 685See also 686.Sx \&I 687and 688.Sx \&B . 689.Ss \&RB 690Text is rendered alternately in roman (the default font) and bold face. 691Whitespace between arguments is omitted in output. 692.Pp 693See 694.Sx \&BI 695for an equivalent example. 696.Pp 697See also 698.Sx \&BI , 699.Sx \&IB , 700.Sx \&BR , 701.Sx \&RI , 702and 703.Sx \&IR . 704.Ss \&RE 705Explicitly close out the scope of a prior 706.Sx \&RS . 707.Ss \&RI 708Text is rendered alternately in roman (the default font) and italics. 709Whitespace between arguments is omitted in output. 710.Pp 711See 712.Sx \&BI 713for an equivalent example. 714.Pp 715See also 716.Sx \&BI , 717.Sx \&IB , 718.Sx \&BR , 719.Sx \&RB , 720and 721.Sx \&IR . 722.Ss \&RS 723Begin a part setting the left margin. 724The left margin controls the offset, following an initial indentation, 725to un-indented text such as that of 726.Sx \&PP . 727This has the following syntax: 728.Bd -filled -offset indent 729.Pf \. Sx \&Rs 730.Op Cm width 731.Ed 732.Pp 733The 734.Cm width 735argument must conform to 736.Sx Scaling Widths . 737If not specified, the saved or default width is used. 738.Ss \&SB 739Text is rendered in small size (one point smaller than the default font) 740bold face. 741.Ss \&SH 742Begin a section. 743The scope of a section is only closed by another section or the end of 744file. 745The paragraph left-margin width is reset to the default. 746.Ss \&SM 747Text is rendered in small size (one point smaller than the default 748font). 749.Ss \&SS 750Begin a sub-section. 751The scope of a sub-section is closed by a subsequent sub-section, 752section, or end of file. 753The paragraph left-margin width is reset to the default. 754.Ss \&TH 755Sets the title of the manual page with the following syntax: 756.Bd -filled -offset indent 757.Pf \. Sx \&TH 758.Cm title section 759.Op Cm date Op Cm source Op Cm volume 760.Ed 761.Pp 762At least the upper-case document 763.Cm title 764and the manual 765.Cm section 766arguments must be provided. 767The 768.Cm date 769argument should be formatted as described in 770.Sx Dates , 771but will be printed verbatim if it is not. 772If the date is not specified, the current date is used. 773The 774.Cm source 775string specifies the organisation providing the utility. 776The 777.Cm volume 778string replaces the default rendered volume, which is dictated by the 779manual section. 780.Pp 781Examples: 782.Pp 783.Dl \&.TH CVS 5 "1992-02-12" GNU 784.Ss \&TP 785Begin a paragraph where the head, if exceeding the indentation width, is 786followed by a newline; if not, the body follows on the same line after a 787buffer to the indentation width. 788Subsequent output lines are indented. 789The syntax is as follows: 790.Bd -filled -offset indent 791.Pf \. Sx \&TP 792.Op Cm width 793.Ed 794.Pp 795The 796.Cm width 797argument must conform to 798.Sx Scaling Widths . 799If specified, it's saved for later paragraph left-margins; if 800unspecified, the saved or default width is used. 801.Pp 802See also 803.Sx \&HP , 804.Sx \&IP , 805.Sx \&LP , 806.Sx \&P , 807and 808.Sx \&PP . 809.Ss \&UC 810Sets the volume for the footer for compatibility with man pages from 811BSD releases. 812The optional first argument specifies which release it is from. 813.Ss \&br 814Breaks the current line. 815Consecutive invocations have no further effect. 816.Pp 817See also 818.Sx \&sp . 819.Ss \&fi 820End literal mode begun by 821.Sx \&nf . 822.Ss \&in 823Indent relative to the current indentation: 824.Pp 825.D1 Pf \. Sx \&in Op Cm width 826.Pp 827If 828.Cm width 829is signed, the new offset is relative. 830Otherwise, it is absolute. 831This value is reset upon the next paragraph, section, or sub-section. 832.Ss \&na 833Don't align to the right margin. 834.Ss \&nf 835Begin literal mode: all subsequent free-form lines have their end of 836line boundaries preserved. 837May be ended by 838.Sx \&fi . 839.Ss \&sp 840Insert vertical spaces into output with the following syntax: 841.Bd -filled -offset indent 842.Pf \. Sx \&sp 843.Op Cm height 844.Ed 845.Pp 846Insert 847.Cm height 848spaces, which must conform to 849.Sx Scaling Widths . 850If 0, this is equivalent to the 851.Sx \&br 852macro. 853Defaults to 1, if unspecified. 854.Pp 855See also 856.Sx \&br . 857.Sh COMPATIBILITY 858This section documents areas of questionable portability between 859implementations of the 860.Nm 861language. 862.Pp 863.Bl -dash -compact 864.It 865In quoted literals, GNU troff allowed pair-wise double-quotes to produce 866a standalone double-quote in formatted output. 867It is not known whether this behaviour is exhibited by other formatters. 868.It 869troff suppresses a newline before 870.Sq \(aq 871macro output; in mandoc, it is an alias for the standard 872.Sq \&. 873control character. 874.It 875The 876.Sq \eh 877.Pq horizontal position , 878.Sq \ev 879.Pq vertical position , 880.Sq \em 881.Pq text colour , 882.Sq \eM 883.Pq text filling colour , 884.Sq \ez 885.Pq zero-length character , 886.Sq \ew 887.Pq string length , 888.Sq \ek 889.Pq horizontal position marker , 890.Sq \eo 891.Pq text overstrike , 892and 893.Sq \es 894.Pq text size 895escape sequences are all discarded in mandoc. 896.It 897The 898.Sq \ef 899scaling unit is accepted by mandoc, but rendered as the default unit. 900.It 901The 902.Sx \&sp 903macro does not accept negative values in mandoc. 904In GNU troff, this would result in strange behaviour. 905.El 906.Sh SEE ALSO 907.Xr man 1 , 908.Xr mandoc 1 , 909.Xr mandoc_char 7 , 910.Xr mdoc 7 , 911.Xr roff 7 , 912.Xr tbl 7 913.Sh HISTORY 914The 915.Nm 916language first appeared as a macro package for the roff typesetting 917system in 918.At v7 . 919It was later rewritten by James Clark as a macro package for groff. 920The stand-alone implementation that is part of the 921.Xr mandoc 1 922utility written by Kristaps Dzonsons appeared in 923.Ox 4.6 . 924.Sh AUTHORS 925This 926.Nm 927reference was written by 928.An Kristaps Dzonsons Aq kristaps@bsd.lv . 929.Sh CAVEATS 930Do not use this language. 931Use 932.Xr mdoc 7 , 933instead. 934