mandoc_char.7

   1 .\"     $Id: mandoc_char.7,v 1.68 2018/03/15 18:10:31 schwarze Exp $
   2 .\"
   3 .\" Copyright (c) 2003 Jason McIntyre <jmc@openbsd.org>
   4 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   5 .\" Copyright (c) 2011, 2013, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
   6 .\"
   7 .\" Permission to use, copy, modify, and distribute this software for any
   8 .\" purpose with or without fee is hereby granted, provided that the above
   9 .\" copyright notice and this permission notice appear in all copies.
  10 .\"
  11 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15 .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18 .\"
  19 .Dd $Mdocdate: March 15 2018 $
  20 .Dt MANDOC_CHAR 7
  21 .Os
  22 .Sh NAME
  23 .Nm mandoc_char
  24 .Nd mandoc special characters
  25 .Sh DESCRIPTION
  26 This page documents the
  27 .Xr roff 7
  28 escape sequences accepted by
  29 .Xr mandoc 1
  30 to represent special characters in
  31 .Xr mdoc 7
  32 and
  33 .Xr man 7
  34 documents.
  35 .Pp
  36 The rendering depends on the
  37 .Xr mandoc 1
  38 output mode; it can be inspected by calling
  39 .Xr man 1
  40 on the
  41 .Nm
  42 manual page with different
  43 .Fl T
  44 arguments.
  45 In ASCII output, the rendering of some characters may be hard
  46 to interpret for the reader.
  47 Many are rendered as descriptive strings like
  48 .Qq <integral> ,
  49 .Qq <degree> ,
  50 or
  51 .Qq <Gamma> ,
  52 which may look ugly, and many are replaced by similar ASCII characters.
  53 In particular, accented characters are usually shown without the accent.
  54 For that reason, try to avoid using any of the special characters
  55 documented here except those discussed in the
  56 .Sx DESCRIPTION ,
  57 unless they are essential for explaining the subject matter at hand,
  58 for example when documenting complicated mathematical functions.
  59 .Pp
  60 In particular, in English manual pages, do not use special-character
  61 escape sequences to represent national language characters in author
  62 names; instead, provide ASCII transcriptions of the names.
  63 .Ss Dashes and Hyphens
  64 In typography there are different types of dashes of various width:
  65 the hyphen (-),
  66 the minus sign (\(mi),
  67 the en-dash (\(en),
  68 and the em-dash (\(em).
  69 .Pp
  70 Hyphens are used for adjectives;
  71 to separate the two parts of a compound word;
  72 or to separate a word across two successive lines of text.
  73 The hyphen does not need to be escaped:
  74 .Bd -unfilled -offset indent
  75 blue-eyed
  76 lorry-driver
  77 .Ed
  78 .Pp
  79 If a word on a text input line contains a hyphen, a formatter may decide
  80 to insert an output line break after the hyphen if that helps filling
  81 the current output line, but the whole word would overflow the line.
  82 If it is important that the word is not broken across lines in this
  83 way, a zero-width space
  84 .Pq Sq \e&
  85 can be inserted before or after the hyphen.
  86 While
  87 .Xr mandoc 1
  88 never breaks the output line after hyphens adjacent to a zero-width
  89 space, after any of the other dash- or hyphen-like characters
  90 represented by escape sequences, or after hyphens inside words in
  91 macro arguments, other software may not respect these rules and may
  92 break the line even in such cases.
  93 .Pp
  94 Some
  95 .Xr roff 7
  96 implementations contains dictionaries allowing to break the line
  97 at syllable boundaries even inside words that contain no hyphens.
  98 Such automatic hyphenation is not supported by
  99 .Xr mandoc 1 ,
 100 which only breaks the line at whitespace, and inside words only
 101 after existing hyphens.
 102 .Pp
 103 The mathematical minus sign is used for negative numbers or subtraction.
 104 It should be written as
 105 .Sq \e(mi :
 106 .Bd -unfilled -offset indent
 107 a = 3 \e(mi 1;
 108 b = \e(mi2;
 109 .Ed
 110 .Pp
 111 The en-dash is used to separate the two elements of a range,
 112 or can be used the same way as an em-dash.
 113 It should be written as
 114 .Sq \e(en :
 115 .Bd -unfilled -offset indent
 116 pp. 95\e(en97.
 117 Go away \e(en or else!
 118 .Ed
 119 .Pp
 120 The em-dash can be used to show an interruption
 121 or can be used the same way as colons, semi-colons, or parentheses.
 122 It should be written as
 123 .Sq \e(em :
 124 .Bd -unfilled -offset indent
 125 Three things \e(em apples, oranges, and bananas.
 126 This is not that \e(em rather, this is that.
 127 .Ed
 128 .Pp
 129 Note:
 130 hyphens, minus signs, and en-dashes look identical under normal ASCII output.
 131 Other formats, such as PostScript, render them correctly,
 132 with differing widths.
 133 .Ss Spaces
 134 To separate words in normal text, for indenting and alignment
 135 in literal context, and when none of the following special cases apply,
 136 just use the normal space character
 137 .Pq Sq \  .
 138 .Pp
 139 When filling text, output lines may be broken between words, i.e. at space
 140 characters.
 141 To prevent a line break between two particular words,
 142 use the unpaddable non-breaking space escape sequence
 143 .Pq Sq \e\ \&
 144 instead of the normal space character.
 145 For example, the input string
 146 .Dq number\e\ 1
 147 will be kept together as
 148 .Dq number\ 1
 149 on the same output line.
 150 .Pp
 151 On request and macro lines, the normal space character serves as an
 152 argument delimiter.
 153 To include whitespace into arguments, quoting is usually the best choice;
 154 see the MACRO SYNTAX section in
 155 .Xr roff 7 .
 156 In some cases, using the non-breaking space escape sequence
 157 .Pq Sq \e\ \&
 158 may be preferable.
 159 .Pp
 160 To escape macro names and to protect whitespace at the end
 161 of input lines, the zero-width space
 162 .Pq Sq \e&
 163 is often useful.
 164 For example, in
 165 .Xr mdoc 7 ,
 166 a normal space character can be displayed in single quotes in either
 167 of the following ways:
 168 .Pp
 169 .Dl .Sq \(dq \(dq
 170 .Dl .Sq \e \e&
 171 .Ss Quotes
 172 On request and macro lines, the double-quote character
 173 .Pq Sq \(dq
 174 is handled specially to allow quoting.
 175 One way to prevent this special handling is by using the
 176 .Sq \e(dq
 177 escape sequence.
 178 .Pp
 179 Note that on text lines, literal double-quote characters can be used
 180 verbatim.
 181 All other quote-like characters can be used verbatim as well,
 182 even on request and macro lines.
 183 .Ss Accents
 184 In output modes supporting such special output characters, for example
 185 .Fl T Cm pdf ,
 186 and sometimes less consistently in
 187 .Fl T Cm utf8 ,
 188 some
 189 .Xr roff 7
 190 formatters convert the following ASCII input characters to the
 191 following Unicode special output characters:
 192 .Bl -column x(ga U+2018 -offset indent
 193 .It \(ga Ta U+2018 Ta left single quotation mark
 194 .It \(aq Ta U+2019 Ta right single quotation mark
 195 .It \(ti Ta U+02DC Ta small tilde
 196 .It \(ha Ta U+02C6 Ta modifier letter circumflex
 197 .El
 198 .Pp
 199 In prose, this automatic substitution is often desirable;
 200 but when these characters have to be displayed as plain ASCII
 201 characters, for example in source code samples, they require
 202 escaping to render as follows:
 203 .Bl -column x(ga U+2018 -offset indent
 204 .It \e(ga Ta U+0060 Ta grave accent
 205 .It \e(aq Ta U+0027 Ta apostrophe
 206 .It \e(ti Ta U+007E Ta tilde
 207 .It \e(ha Ta U+005E Ta circumflex accent
 208 .El
 209 .Ss Periods
 210 The period
 211 .Pq Sq \&.
 212 is handled specially at the beginning of an input line,
 213 where it introduces a
 214 .Xr roff 7
 215 request or a macro, and when appearing alone as a macro argument in
 216 .Xr mdoc 7 .
 217 In such situations, prepend a zero-width space
 218 .Pq Sq \e&.
 219 to make it behave like normal text.
 220 .Pp
 221 Do not use the
 222 .Sq \e.
 223 escape sequence.
 224 It does not prevent special handling of the period.
 225 .Ss Backslashes
 226 To include a literal backslash
 227 .Pq Sq \e
 228 into the output, use the
 229 .Pq Sq \ee
 230 escape sequence.
 231 .Pp
 232 Note that doubling it
 233 .Pq Sq \e\e
 234 is not the right way to output a backslash.
 235 Because
 236 .Xr mandoc 1
 237 does not implement full
 238 .Xr roff 7
 239 functionality, it may work with
 240 .Xr mandoc 1 ,
 241 but it may have weird effects on complete
 242 .Xr roff 7
 243 implementations.
 244 .Sh SPECIAL CHARACTERS
 245 Special characters are encoded as
 246 .Sq \eX
 247 .Pq for a one-character escape ,
 248 .Sq \e(XX
 249 .Pq two-character ,
 250 and
 251 .Sq \e[N]
 252 .Pq N-character .
 253 For details, see the
 254 .Em Special Characters
 255 subsection of the
 256 .Xr roff 7
 257 manual.
 258 .Pp
 259 Spacing:
 260 .Bl -column "Input" "Description" -offset indent -compact
 261 .It Em Input Ta Em Description
 262 .It Sq \e\ \& Ta unpaddable non-breaking space
 263 .It \e\(ti   Ta paddable non-breaking space
 264 .It \e0      Ta unpaddable, breaking digit-width space
 265 .It \e|      Ta one-sixth \e(em narrow space, zero width in nroff mode
 266 .It \e^      Ta one-twelfth \e(em half-narrow space, zero width in nroff
 267 .It \e&      Ta zero-width space
 268 .It \e%      Ta zero-width space allowing hyphenation
 269 .El
 270 .Pp
 271 Lines:
 272 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 273 .It Em Input Ta Em Rendered Ta Em Description
 274 .It \e(ba    Ta \(ba        Ta bar
 275 .It \e(br    Ta \(br        Ta box rule
 276 .It \e(ul    Ta \(ul        Ta underscore
 277 .It \e(ru    Ta \(ru        Ta underscore (width 0.5m)
 278 .It \e(rn    Ta \(rn        Ta overline
 279 .It \e(bb    Ta \(bb        Ta broken bar
 280 .It \e(sl    Ta \(sl        Ta forward slash
 281 .It \e(rs    Ta \(rs        Ta backward slash
 282 .El
 283 .Pp
 284 Text markers:
 285 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 286 .It Em Input Ta Em Rendered Ta Em Description
 287 .It \e(ci    Ta \(ci        Ta circle
 288 .It \e(bu    Ta \(bu        Ta bullet
 289 .It \e(dd    Ta \(dd        Ta double dagger
 290 .It \e(dg    Ta \(dg        Ta dagger
 291 .It \e(lz    Ta \(lz        Ta lozenge
 292 .It \e(sq    Ta \(sq        Ta white square
 293 .It \e(ps    Ta \(ps        Ta paragraph
 294 .It \e(sc    Ta \(sc        Ta section
 295 .It \e(lh    Ta \(lh        Ta left hand
 296 .It \e(rh    Ta \(rh        Ta right hand
 297 .It \e(at    Ta \(at        Ta at
 298 .It \e(sh    Ta \(sh        Ta hash (pound)
 299 .It \e(CR    Ta \(CR        Ta carriage return
 300 .It \e(OK    Ta \(OK        Ta check mark
 301 .It \e(CL    Ta \(CL        Ta club suit
 302 .It \e(SP    Ta \(SP        Ta spade suit
 303 .It \e(HE    Ta \(HE        Ta heart suit
 304 .It \e(DI    Ta \(DI        Ta diamond suit
 305 .El
 306 .Pp
 307 Legal symbols:
 308 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 309 .It Em Input Ta Em Rendered Ta Em Description
 310 .It \e(co    Ta \(co        Ta copyright
 311 .It \e(rg    Ta \(rg        Ta registered
 312 .It \e(tm    Ta \(tm        Ta trademarked
 313 .El
 314 .Pp
 315 Punctuation:
 316 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 317 .It Em Input Ta Em Rendered Ta Em Description
 318 .It \e(em    Ta \(em        Ta em-dash
 319 .It \e(en    Ta \(en        Ta en-dash
 320 .It \e(hy    Ta \(hy        Ta hyphen
 321 .It \ee      Ta \e          Ta back-slash
 322 .It \e.      Ta \.          Ta period
 323 .It \e(r!    Ta \(r!        Ta upside-down exclamation
 324 .It \e(r?    Ta \(r?        Ta upside-down question
 325 .El
 326 .Pp
 327 Quotes:
 328 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 329 .It Em Input Ta Em Rendered Ta Em Description
 330 .It \e(Bq    Ta \(Bq        Ta right low double-quote
 331 .It \e(bq    Ta \(bq        Ta right low single-quote
 332 .It \e(lq    Ta \(lq        Ta left double-quote
 333 .It \e(rq    Ta \(rq        Ta right double-quote
 334 .It \e(oq    Ta \(oq        Ta left single-quote
 335 .It \e(cq    Ta \(cq        Ta right single-quote
 336 .It \e(aq    Ta \(aq        Ta apostrophe quote (text)
 337 .It \e(dq    Ta \(dq        Ta double quote (text)
 338 .It \e(Fo    Ta \(Fo        Ta left guillemet
 339 .It \e(Fc    Ta \(Fc        Ta right guillemet
 340 .It \e(fo    Ta \(fo        Ta left single guillemet
 341 .It \e(fc    Ta \(fc        Ta right single guillemet
 342 .El
 343 .Pp
 344 Brackets:
 345 .Bl -column "xxbracketrightbtx" Rendered Description -offset indent -compact
 346 .It Em Input Ta Em Rendered Ta Em Description
 347 .It \e(lB    Ta \(lB        Ta left bracket
 348 .It \e(rB    Ta \(rB        Ta right bracket
 349 .It \e(lC    Ta \(lC        Ta left brace
 350 .It \e(rC    Ta \(rC        Ta right brace
 351 .It \e(la    Ta \(la        Ta left angle
 352 .It \e(ra    Ta \(ra        Ta right angle
 353 .It \e(bv    Ta \(bv        Ta brace extension
 354 .It \e[braceex] Ta \[braceex] Ta brace extension
 355 .It \e[bracketlefttp] Ta \[bracketlefttp] Ta top-left hooked bracket
 356 .It \e[bracketleftbt] Ta \[bracketleftbt] Ta bottom-left hooked bracket
 357 .It \e[bracketleftex] Ta \[bracketleftex] Ta left hooked bracket extension
 358 .It \e[bracketrighttp] Ta \[bracketrighttp] Ta top-right hooked bracket
 359 .It \e[bracketrightbt] Ta \[bracketrightbt] Ta bottom-right hooked bracket
 360 .It \e[bracketrightex] Ta \[bracketrightex] Ta right hooked bracket extension
 361 .It \e(lt    Ta \(lt        Ta top-left hooked brace
 362 .It \e[bracelefttp] Ta \[bracelefttp] Ta top-left hooked brace
 363 .It \e(lk    Ta \(lk        Ta mid-left hooked brace
 364 .It \e[braceleftmid] Ta \[braceleftmid] Ta mid-left hooked brace
 365 .It \e(lb    Ta \(lb        Ta bottom-left hooked brace
 366 .It \e[braceleftbt] Ta \[braceleftbt] Ta bottom-left hooked brace
 367 .It \e[braceleftex] Ta \[braceleftex] Ta left hooked brace extension
 368 .It \e(rt    Ta \(rt        Ta top-left hooked brace
 369 .It \e[bracerighttp] Ta \[bracerighttp] Ta top-right hooked brace
 370 .It \e(rk    Ta \(rk        Ta mid-right hooked brace
 371 .It \e[bracerightmid] Ta \[bracerightmid] Ta mid-right hooked brace
 372 .It \e(rb    Ta \(rb        Ta bottom-right hooked brace
 373 .It \e[bracerightbt] Ta \[bracerightbt] Ta bottom-right hooked brace
 374 .It \e[bracerightex] Ta \[bracerightex] Ta right hooked brace extension
 375 .It \e[parenlefttp] Ta \[parenlefttp] Ta top-left hooked parenthesis
 376 .It \e[parenleftbt] Ta \[parenleftbt] Ta bottom-left hooked parenthesis
 377 .It \e[parenleftex] Ta \[parenleftex] Ta left hooked parenthesis extension
 378 .It \e[parenrighttp] Ta \[parenrighttp] Ta top-right hooked parenthesis
 379 .It \e[parenrightbt] Ta \[parenrightbt] Ta bottom-right hooked parenthesis
 380 .It \e[parenrightex] Ta \[parenrightex] Ta right hooked parenthesis extension
 381 .El
 382 .Pp
 383 Arrows:
 384 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 385 .It Em Input Ta Em Rendered Ta Em Description
 386 .It \e(<-    Ta \(<-        Ta left arrow
 387 .It \e(->    Ta \(->        Ta right arrow
 388 .It \e(<>    Ta \(<>        Ta left-right arrow
 389 .It \e(da    Ta \(da        Ta down arrow
 390 .It \e(ua    Ta \(ua        Ta up arrow
 391 .It \e(va    Ta \(va        Ta up-down arrow
 392 .It \e(lA    Ta \(lA        Ta left double-arrow
 393 .It \e(rA    Ta \(rA        Ta right double-arrow
 394 .It \e(hA    Ta \(hA        Ta left-right double-arrow
 395 .It \e(uA    Ta \(uA        Ta up double-arrow
 396 .It \e(dA    Ta \(dA        Ta down double-arrow
 397 .It \e(vA    Ta \(vA        Ta up-down double-arrow
 398 .It \e(an    Ta \(an        Ta horizontal arrow extension
 399 .El
 400 .Pp
 401 Logical:
 402 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 403 .It Em Input Ta Em Rendered Ta Em Description
 404 .It \e(AN    Ta \(AN        Ta logical and
 405 .It \e(OR    Ta \(OR        Ta logical or
 406 .It \e(no    Ta \(no        Ta logical not
 407 .It \e[tno]  Ta \[tno]      Ta logical not (text)
 408 .It \e(te    Ta \(te        Ta existential quantifier
 409 .It \e(fa    Ta \(fa        Ta universal quantifier
 410 .It \e(st    Ta \(st        Ta such that
 411 .It \e(tf    Ta \(tf        Ta therefore
 412 .It \e(3d    Ta \(3d        Ta therefore
 413 .It \e(or    Ta \(or        Ta bitwise or
 414 .El
 415 .Pp
 416 Mathematical:
 417 .Bl -column "xxcoproductxx" "Rendered" "Description" -offset indent -compact
 418 .It Em Input Ta Em Rendered Ta Em Description
 419 .It \e(pl    Ta \(pl        Ta plus
 420 .It \e(mi    Ta \(mi        Ta minus
 421 .It \e-      Ta \-          Ta minus (text)
 422 .It \e(-+    Ta \(-+        Ta minus-plus
 423 .It \e(+-    Ta \(+-        Ta plus-minus
 424 .It \e[t+-]  Ta \[t+-]      Ta plus-minus (text)
 425 .It \e(pc    Ta \(pc        Ta center-dot
 426 .It \e(mu    Ta \(mu        Ta multiply
 427 .It \e[tmu]  Ta \[tmu]      Ta multiply (text)
 428 .It \e(c*    Ta \(c*        Ta circle-multiply
 429 .It \e(c+    Ta \(c+        Ta circle-plus
 430 .It \e(di    Ta \(di        Ta divide
 431 .It \e[tdi]  Ta \[tdi]      Ta divide (text)
 432 .It \e(f/    Ta \(f/        Ta fraction
 433 .It \e(**    Ta \(**        Ta asterisk
 434 .It \e(<=    Ta \(<=        Ta less-than-equal
 435 .It \e(>=    Ta \(>=        Ta greater-than-equal
 436 .It \e(<<    Ta \(<<        Ta much less
 437 .It \e(>>    Ta \(>>        Ta much greater
 438 .It \e(eq    Ta \(eq        Ta equal
 439 .It \e(!=    Ta \(!=        Ta not equal
 440 .It \e(==    Ta \(==        Ta equivalent
 441 .It \e(ne    Ta \(ne        Ta not equivalent
 442 .It \e(ap    Ta \(ap        Ta tilde operator
 443 .It \e(|=    Ta \(|=        Ta asymptotically equal
 444 .It \e(=\(ti Ta \(=~        Ta approximately equal
 445 .It \e(\(ti\(ti Ta \(~~        Ta almost equal
 446 .It \e(\(ti= Ta \(~=        Ta almost equal
 447 .It \e(pt    Ta \(pt        Ta proportionate
 448 .It \e(es    Ta \(es        Ta empty set
 449 .It \e(mo    Ta \(mo        Ta element
 450 .It \e(nm    Ta \(nm        Ta not element
 451 .It \e(sb    Ta \(sb        Ta proper subset
 452 .It \e(nb    Ta \(nb        Ta not subset
 453 .It \e(sp    Ta \(sp        Ta proper superset
 454 .It \e(nc    Ta \(nc        Ta not superset
 455 .It \e(ib    Ta \(ib        Ta reflexive subset
 456 .It \e(ip    Ta \(ip        Ta reflexive superset
 457 .It \e(ca    Ta \(ca        Ta intersection
 458 .It \e(cu    Ta \(cu        Ta union
 459 .It \e(/_    Ta \(/_        Ta angle
 460 .It \e(pp    Ta \(pp        Ta perpendicular
 461 .It \e(is    Ta \(is        Ta integral
 462 .It \e[integral] Ta \[integral] Ta integral
 463 .It \e[sum]    Ta \[sum]   Ta summation
 464 .It \e[product] Ta \[product] Ta product
 465 .It \e[coproduct] Ta \[coproduct] Ta coproduct
 466 .It \e(gr    Ta \(gr        Ta gradient
 467 .It \e(sr    Ta \(sr        Ta square root
 468 .It \e[sqrt] Ta \[sqrt]     Ta square root
 469 .It \e(lc    Ta \(lc        Ta left-ceiling
 470 .It \e(rc    Ta \(rc        Ta right-ceiling
 471 .It \e(lf    Ta \(lf        Ta left-floor
 472 .It \e(rf    Ta \(rf        Ta right-floor
 473 .It \e(if    Ta \(if        Ta infinity
 474 .It \e(Ah    Ta \(Ah        Ta aleph
 475 .It \e(Im    Ta \(Im        Ta imaginary
 476 .It \e(Re    Ta \(Re        Ta real
 477 .It \e(wp    Ta \(wp        Ta Weierstrass p
 478 .It \e(pd    Ta \(pd        Ta partial differential
 479 .It \e(-h    Ta \(-h        Ta Planck constant over 2\(*p
 480 .It \e[hbar] Ta \[hbar]     Ta Planck constant over 2\(*p
 481 .It \e(12    Ta \(12        Ta one-half
 482 .It \e(14    Ta \(14        Ta one-fourth
 483 .It \e(34    Ta \(34        Ta three-fourths
 484 .It \e(18    Ta \(18        Ta one-eighth
 485 .It \e(38    Ta \(38        Ta three-eighths
 486 .It \e(58    Ta \(58        Ta five-eighths
 487 .It \e(78    Ta \(78        Ta seven-eighths
 488 .It \e(S1    Ta \(S1        Ta superscript 1
 489 .It \e(S2    Ta \(S2        Ta superscript 2
 490 .It \e(S3    Ta \(S3        Ta superscript 3
 491 .El
 492 .Pp
 493 Ligatures:
 494 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 495 .It Em Input Ta Em Rendered Ta Em Description
 496 .It \e(ff    Ta \(ff        Ta ff ligature
 497 .It \e(fi    Ta \(fi        Ta fi ligature
 498 .It \e(fl    Ta \(fl        Ta fl ligature
 499 .It \e(Fi    Ta \(Fi        Ta ffi ligature
 500 .It \e(Fl    Ta \(Fl        Ta ffl ligature
 501 .It \e(AE    Ta \(AE        Ta AE
 502 .It \e(ae    Ta \(ae        Ta ae
 503 .It \e(OE    Ta \(OE        Ta OE
 504 .It \e(oe    Ta \(oe        Ta oe
 505 .It \e(ss    Ta \(ss        Ta German eszett
 506 .It \e(IJ    Ta \(IJ        Ta IJ ligature
 507 .It \e(ij    Ta \(ij        Ta ij ligature
 508 .El
 509 .Pp
 510 Accents:
 511 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 512 .It Em Input Ta Em Rendered Ta Em Description
 513 .It \e(a"    Ta \(a"        Ta Hungarian umlaut
 514 .It \e(a-    Ta \(a-        Ta macron
 515 .It \e(a.    Ta \(a.        Ta dotted
 516 .It \e(a^    Ta \(a^        Ta circumflex
 517 .It \e(aa    Ta \(aa        Ta acute
 518 .It \e\(aq   Ta \'          Ta acute
 519 .It \e(ga    Ta \(ga        Ta grave
 520 .It \e\(ga   Ta \`          Ta grave
 521 .It \e(ab    Ta \(ab        Ta breve
 522 .It \e(ac    Ta \(ac        Ta cedilla
 523 .It \e(ad    Ta \(ad        Ta dieresis
 524 .It \e(ah    Ta \(ah        Ta caron
 525 .It \e(ao    Ta \(ao        Ta ring
 526 .It \e(a\(ti Ta \(a~        Ta tilde
 527 .It \e(ho    Ta \(ho        Ta ogonek
 528 .It \e(ha    Ta \(ha        Ta hat (text)
 529 .It \e(ti    Ta \(ti        Ta tilde (text)
 530 .El
 531 .Pp
 532 Accented letters:
 533 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 534 .It Em Input Ta Em Rendered Ta Em Description
 535 .It \e(\(aqA Ta \('A        Ta acute A
 536 .It \e(\(aqE Ta \('E        Ta acute E
 537 .It \e(\(aqI Ta \('I        Ta acute I
 538 .It \e(\(aqO Ta \('O        Ta acute O
 539 .It \e(\(aqU Ta \('U        Ta acute U
 540 .It \e(\(aqa Ta \('a        Ta acute a
 541 .It \e(\(aqe Ta \('e        Ta acute e
 542 .It \e(\(aqi Ta \('i        Ta acute i
 543 .It \e(\(aqo Ta \('o        Ta acute o
 544 .It \e(\(aqu Ta \('u        Ta acute u
 545 .It \e(\(gaA Ta \(`A        Ta grave A
 546 .It \e(\(gaE Ta \(`E        Ta grave E
 547 .It \e(\(gaI Ta \(`I        Ta grave I
 548 .It \e(\(gaO Ta \(`O        Ta grave O
 549 .It \e(\(gaU Ta \(`U        Ta grave U
 550 .It \e(\(gaa Ta \(`a        Ta grave a
 551 .It \e(\(gae Ta \(`e        Ta grave e
 552 .It \e(\(gai Ta \(`i        Ta grave i
 553 .It \e(\(gao Ta \(`i        Ta grave o
 554 .It \e(\(gau Ta \(`u        Ta grave u
 555 .It \e(\(tiA Ta \(~A        Ta tilde A
 556 .It \e(\(tiN Ta \(~N        Ta tilde N
 557 .It \e(\(tiO Ta \(~O        Ta tilde O
 558 .It \e(\(tia Ta \(~a        Ta tilde a
 559 .It \e(\(tin Ta \(~n        Ta tilde n
 560 .It \e(\(tio Ta \(~o        Ta tilde o
 561 .It \e(:A    Ta \(:A        Ta dieresis A
 562 .It \e(:E    Ta \(:E        Ta dieresis E
 563 .It \e(:I    Ta \(:I        Ta dieresis I
 564 .It \e(:O    Ta \(:O        Ta dieresis O
 565 .It \e(:U    Ta \(:U        Ta dieresis U
 566 .It \e(:a    Ta \(:a        Ta dieresis a
 567 .It \e(:e    Ta \(:e        Ta dieresis e
 568 .It \e(:i    Ta \(:i        Ta dieresis i
 569 .It \e(:o    Ta \(:o        Ta dieresis o
 570 .It \e(:u    Ta \(:u        Ta dieresis u
 571 .It \e(:y    Ta \(:y        Ta dieresis y
 572 .It \e(^A    Ta \(^A        Ta circumflex A
 573 .It \e(^E    Ta \(^E        Ta circumflex E
 574 .It \e(^I    Ta \(^I        Ta circumflex I
 575 .It \e(^O    Ta \(^O        Ta circumflex O
 576 .It \e(^U    Ta \(^U        Ta circumflex U
 577 .It \e(^a    Ta \(^a        Ta circumflex a
 578 .It \e(^e    Ta \(^e        Ta circumflex e
 579 .It \e(^i    Ta \(^i        Ta circumflex i
 580 .It \e(^o    Ta \(^o        Ta circumflex o
 581 .It \e(^u    Ta \(^u        Ta circumflex u
 582 .It \e(,C    Ta \(,C        Ta cedilla C
 583 .It \e(,c    Ta \(,c        Ta cedilla c
 584 .It \e(/L    Ta \(/L        Ta stroke L
 585 .It \e(/l    Ta \(/l        Ta stroke l
 586 .It \e(/O    Ta \(/O        Ta stroke O
 587 .It \e(/o    Ta \(/o        Ta stroke o
 588 .It \e(oA    Ta \(oA        Ta ring A
 589 .It \e(oa    Ta \(oa        Ta ring a
 590 .El
 591 .Pp
 592 Special letters:
 593 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 594 .It Em Input Ta Em Rendered Ta Em Description
 595 .It \e(-D    Ta \(-D        Ta Eth
 596 .It \e(Sd    Ta \(Sd        Ta eth
 597 .It \e(TP    Ta \(TP        Ta Thorn
 598 .It \e(Tp    Ta \(Tp        Ta thorn
 599 .It \e(.i    Ta \(.i        Ta dotless i
 600 .It \e(.j    Ta \(.j        Ta dotless j
 601 .El
 602 .Pp
 603 Currency:
 604 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 605 .It Em Input Ta Em Rendered Ta Em Description
 606 .It \e(Do    Ta \(Do        Ta dollar
 607 .It \e(ct    Ta \(ct        Ta cent
 608 .It \e(Eu    Ta \(Eu        Ta Euro symbol
 609 .It \e(eu    Ta \(eu        Ta Euro symbol
 610 .It \e(Ye    Ta \(Ye        Ta yen
 611 .It \e(Po    Ta \(Po        Ta pound
 612 .It \e(Cs    Ta \(Cs        Ta Scandinavian
 613 .It \e(Fn    Ta \(Fn        Ta florin
 614 .El
 615 .Pp
 616 Units:
 617 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 618 .It Em Input Ta Em Rendered Ta Em Description
 619 .It \e(de    Ta \(de        Ta degree
 620 .It \e(%0    Ta \(%0        Ta per-thousand
 621 .It \e(fm    Ta \(fm        Ta minute
 622 .It \e(sd    Ta \(sd        Ta second
 623 .It \e(mc    Ta \(mc        Ta micro
 624 .It \e(Of    Ta \(Of        Ta Spanish female ordinal
 625 .It \e(Om    Ta \(Om        Ta Spanish masculine ordinal
 626 .El
 627 .Pp
 628 Greek letters:
 629 .Bl -column "Input" "Rendered" "Description" -offset indent -compact
 630 .It Em Input Ta Em Rendered Ta Em Description
 631 .It \e(*A    Ta \(*A        Ta Alpha
 632 .It \e(*B    Ta \(*B        Ta Beta
 633 .It \e(*G    Ta \(*G        Ta Gamma
 634 .It \e(*D    Ta \(*D        Ta Delta
 635 .It \e(*E    Ta \(*E        Ta Epsilon
 636 .It \e(*Z    Ta \(*Z        Ta Zeta
 637 .It \e(*Y    Ta \(*Y        Ta Eta
 638 .It \e(*H    Ta \(*H        Ta Theta
 639 .It \e(*I    Ta \(*I        Ta Iota
 640 .It \e(*K    Ta \(*K        Ta Kappa
 641 .It \e(*L    Ta \(*L        Ta Lambda
 642 .It \e(*M    Ta \(*M        Ta Mu
 643 .It \e(*N    Ta \(*N        Ta Nu
 644 .It \e(*C    Ta \(*C        Ta Xi
 645 .It \e(*O    Ta \(*O        Ta Omicron
 646 .It \e(*P    Ta \(*P        Ta Pi
 647 .It \e(*R    Ta \(*R        Ta Rho
 648 .It \e(*S    Ta \(*S        Ta Sigma
 649 .It \e(*T    Ta \(*T        Ta Tau
 650 .It \e(*U    Ta \(*U        Ta Upsilon
 651 .It \e(*F    Ta \(*F        Ta Phi
 652 .It \e(*X    Ta \(*X        Ta Chi
 653 .It \e(*Q    Ta \(*Q        Ta Psi
 654 .It \e(*W    Ta \(*W        Ta Omega
 655 .It \e(*a    Ta \(*a        Ta alpha
 656 .It \e(*b    Ta \(*b        Ta beta
 657 .It \e(*g    Ta \(*g        Ta gamma
 658 .It \e(*d    Ta \(*d        Ta delta
 659 .It \e(*e    Ta \(*e        Ta epsilon
 660 .It \e(*z    Ta \(*z        Ta zeta
 661 .It \e(*y    Ta \(*y        Ta eta
 662 .It \e(*h    Ta \(*h        Ta theta
 663 .It \e(*i    Ta \(*i        Ta iota
 664 .It \e(*k    Ta \(*k        Ta kappa
 665 .It \e(*l    Ta \(*l        Ta lambda
 666 .It \e(*m    Ta \(*m        Ta mu
 667 .It \e(*n    Ta \(*n        Ta nu
 668 .It \e(*c    Ta \(*c        Ta xi
 669 .It \e(*o    Ta \(*o        Ta omicron
 670 .It \e(*p    Ta \(*p        Ta pi
 671 .It \e(*r    Ta \(*r        Ta rho
 672 .It \e(*s    Ta \(*s        Ta sigma
 673 .It \e(*t    Ta \(*t        Ta tau
 674 .It \e(*u    Ta \(*u        Ta upsilon
 675 .It \e(*f    Ta \(*f        Ta phi
 676 .It \e(*x    Ta \(*x        Ta chi
 677 .It \e(*q    Ta \(*q        Ta psi
 678 .It \e(*w    Ta \(*w        Ta omega
 679 .It \e(+h    Ta \(+h        Ta theta variant
 680 .It \e(+f    Ta \(+f        Ta phi variant
 681 .It \e(+p    Ta \(+p        Ta pi variant
 682 .It \e(+e    Ta \(+e        Ta epsilon variant
 683 .It \e(ts    Ta \(ts        Ta sigma terminal
 684 .El
 685 .Sh PREDEFINED STRINGS
 686 Predefined strings are inherited from the macro packages of historical
 687 troff implementations.
 688 They are
 689 .Em not recommended
 690 for use, as they differ across implementations.
 691 Manuals using these predefined strings are almost certainly not
 692 portable.
 693 .Pp
 694 Their syntax is similar to special characters, using
 695 .Sq \e*X
 696 .Pq for a one-character escape ,
 697 .Sq \e*(XX
 698 .Pq two-character ,
 699 and
 700 .Sq \e*[N]
 701 .Pq N-character .
 702 For details, see the
 703 .Em Predefined Strings
 704 subsection of the
 705 .Xr roff 7
 706 manual.
 707 .Bl -column "Input" "Rendered" "Description" -offset indent
 708 .It Em Input Ta Em Rendered Ta Em Description
 709 .It \e*(Ba   Ta \*(Ba       Ta vertical bar
 710 .It \e*(Ne   Ta \*(Ne       Ta not equal
 711 .It \e*(Ge   Ta \*(Ge       Ta greater-than-equal
 712 .It \e*(Le   Ta \*(Le       Ta less-than-equal
 713 .It \e*(Gt   Ta \*(Gt       Ta greater-than
 714 .It \e*(Lt   Ta \*(Lt       Ta less-than
 715 .It \e*(Pm   Ta \*(Pm       Ta plus-minus
 716 .It \e*(If   Ta \*(If       Ta infinity
 717 .It \e*(Pi   Ta \*(Pi       Ta pi
 718 .It \e*(Na   Ta \*(Na       Ta NaN
 719 .It \e*(Am   Ta \*(Am       Ta ampersand
 720 .It \e*R     Ta \*R         Ta restricted mark
 721 .It \e*(Tm   Ta \*(Tm       Ta trade mark
 722 .It \e*q     Ta \*q         Ta double-quote
 723 .It \e*(Rq   Ta \*(Rq       Ta right-double-quote
 724 .It \e*(Lq   Ta \*(Lq       Ta left-double-quote
 725 .It \e*(lp   Ta \*(lp       Ta right-parenthesis
 726 .It \e*(rp   Ta \*(rp       Ta left-parenthesis
 727 .It \e*(lq   Ta \*(lq       Ta left double-quote
 728 .It \e*(rq   Ta \*(rq       Ta right double-quote
 729 .It \e*(ua   Ta \*(ua       Ta up arrow
 730 .It \e*(va   Ta \*(va       Ta up-down arrow
 731 .It \e*(<=   Ta \*(<=       Ta less-than-equal
 732 .It \e*(>=   Ta \*(>=       Ta greater-than-equal
 733 .It \e*(aa   Ta \*(aa       Ta acute
 734 .It \e*(ga   Ta \*(ga       Ta grave
 735 .It \e*(Px   Ta \*(Px       Ta POSIX standard name
 736 .It \e*(Ai   Ta \*(Ai       Ta ANSI standard name
 737 .El
 738 .Sh UNICODE CHARACTERS
 739 The escape sequences
 740 .Pp
 741 .Dl \e[uXXXX] and \eC\(aquXXXX\(aq
 742 .Pp
 743 are interpreted as Unicode codepoints.
 744 The codepoint must be in the range above U+0080 and less than U+10FFFF.
 745 For compatibility, the hexadecimal digits
 746 .Sq A
 747 to
 748 .Sq F
 749 must be given as uppercase characters,
 750 and points must be zero-padded to four characters; if
 751 greater than four characters, no zero padding is allowed.
 752 Unicode surrogates are not allowed.
 753 .Sh NUMBERED CHARACTERS
 754 For backward compatibility with existing manuals,
 755 .Xr mandoc 1
 756 also supports the
 757 .Pp
 758 .Dl \eN\(aq Ns Ar number Ns \(aq
 759 .Pp
 760 escape sequence, inserting the character
 761 .Ar number
 762 from the current character set into the output.
 763 Of course, this is inherently non-portable and is already marked
 764 as deprecated in the Heirloom roff manual.
 765 For example, do not use \eN\(aq34\(aq, use \e(dq, or even the plain
 766 .Sq \(dq
 767 character where possible.
 768 .Sh COMPATIBILITY
 769 This section documents compatibility between mandoc and other
 770 troff implementations, at this time limited to GNU troff
 771 .Pq Qq groff .
 772 .Pp
 773 .Bl -dash -compact
 774 .It
 775 The \eN\(aq\(aq escape sequence is limited to printable characters; in
 776 groff, it accepts arbitrary character numbers.
 777 .It
 778 In
 779 .Fl T Ns Cm ascii ,
 780 the
 781 \e(ss, \e(nm, \e(nb, \e(nc, \e(ib, \e(ip, \e(pp, \e[sum], \e[product],
 782 \e[coproduct], \e(gr, \e(-h, and \e(a. special characters render
 783 differently between mandoc and groff.
 784 .It
 785 In
 786 .Fl T Ns Cm html ,
 787 the \e(\(ti=, \e(nb, and \e(nc special characters render differently
 788 between mandoc and groff.
 789 .It
 790 The
 791 .Fl T Ns Cm ps
 792 and
 793 .Fl T Ns Cm pdf
 794 modes format like
 795 .Fl T Ns Cm ascii
 796 instead of rendering glyphs as in groff.
 797 .It
 798 The \e[radicalex], \e[sqrtex], and \e(ru special characters have been omitted
 799 from mandoc either because they are poorly documented or they have no
 800 known representation.
 801 .El
 802 .Sh SEE ALSO
 803 .Xr mandoc 1 ,
 804 .Xr man 7 ,
 805 .Xr mdoc 7 ,
 806 .Xr roff 7
 807 .Sh AUTHORS
 808 The
 809 .Nm
 810 manual page was written by
 811 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .
 812 .Sh CAVEATS
 813 The predefined string
 814 .Sq \e*(Ba
 815 mimics the behaviour of the
 816 .Sq \&|
 817 character in
 818 .Xr mdoc 7 ;
 819 thus, if you wish to render a vertical bar with no side effects, use
 820 the
 821 .Sq \e(ba
 822 escape.