Provided by: groff_1.23.0-3build2_amd64 bug

Name

       groff_char - GNU roff special character and glyph repertoire

Description

       The  GNU  roff  typesetting system has a large glyph repertoire suitable for production of
       varied literary, professional, technical, and mathematical documents.   groff  works  with
       characters; an output device renders glyphs.  groff's input character set is restricted to
       that defined by the standards ISO Latin-1 (ISO 8859-1) and  CCSID  “code  page”  1047  (an
       EBCDIC  arrangement  of Latin-1).  For ease of document maintenance in UTF-8 environments,
       it is advisable to use only the Unicode basic Latin code points, a subset of  all  of  the
       foregoing  historically referred to as US-ASCII, which has only 94 visible, printable code
       points.  In groff, these are termed ordinary characters.  Often, many more are desired  in
       output.

       AT&T  troff  in  the  1970s  faced  a  similar  problem:  the available typesetter's glyph
       repertoire differed from that of the computers that controlled it.  troff's solution was a
       form  of  escape  sequence known as a special character to access several dozen additional
       glyphs available in the fonts prepared for mounting in the phototypesetter.  These  glyphs
       were  mapped  onto  a  two-character  name space for a degree of mnemonic convenience; for
       example, the escape sequence \(aa encoded an acute accent and \(sc a section sign.

       groff has lifted historical roff  limitations  on  special  character  name  lengths,  but
       recognizes and retains compatibility with the historical names.  groff expands the lexicon
       of glyphs available by name and permits users to define their own special character escape
       sequences  with  the  char  request.   Special  character names are groff identifiers; see
       section “Identifiers” in groff(7).   Our  discussion  uses  the  terms  “glyph  name”  and
       “special   character  name”  interchangeably;  we  assume  no  character  translations  or
       redefinitions.

       This document lists all of the glyph names predefined by groff's  font  description  files
       and  presents the systematic notation by which it enables access to arbitrary Unicode code
       points and construction of composite glyphs.  Glyphs listed may  be  unavailable,  or  may
       vary  in  appearance,  depending  on  the  output device and font chosen when the page was
       formatted.  This page was rendered for device utf8 using font R.

       A few escape sequences that are not groff special characters also  produce  glyphs;  these
       exist  for  syntactical or historical reasons.  \', \`, \-, and \_ are translated on input
       to the special character escape sequences \[aa], \[ga],  \[-],  and  \[ul],  respectively.
       Others  include  \\,  \. (backslash-dot), and \e; see groff(7).  A small number of special
       characters represent glyphs that are not encoded in Unicode; examples include the baseline
       rule \[ru] and the Bell System logo \[bs].

       In  groff, you can test output device support for any character (ordinary or special) with
       the conditional expression operator “c”.
              .ie c \[bs] \{Welcome to the \[bs] Bell System;
              did you get the Wehrmacht helmet or the Death Star?\}
              .el No Bell System logo.

       For brevity in the remainder of this document, we shall refer to systems conforming to the
       ISO 646:1991 IRV, ISO 8859, or ISO 10646 (“Unicode”) character encoding standards as “ISO”
       systems, and those employing IBM code page 1047 as “EBCDIC” systems.   That  said,  EBCDIC
       systems that support groff are known to also support UTF-8.

       While  groff accepts eight-bit encoded input, not all such code points are valid as input.
       On ISO platforms, character codes 0, 11, 13–31, and 128–159 are invalid.  (This is all  C0
       and  C1  controls except for SOH through LF [Control+A to Control+J], and FF [Control+L].)
       On EBCDIC platforms, 0, 8–9, 11, 13–20, 23–31, and 48–63 are invalid.  Some of these  code
       points  are  used  by groff for internal purposes, which is one reason it does not support
       UTF-8 natively.

   Fundamental character set
       The ordinary characters catalogued  above,  plus  the  space,  tab,  newline,  and  leader
       (Control+A), form the fundamental character set for groff input; anything in the language,
       even over one million code points in Unicode, can be expressed using it.  On ISO  systems,
       code  points  in  the range 33–126 comprise a common set of printable glyphs in all of the
       aforementioned ISO character encoding standards.  It is this character set and (with  some
       noteworthy  exceptions)  the  corresponding  glyph  repertoire  for  which  AT&T troff was
       implemented.  On EBCDIC systems, printable characters are in the range 66–201 and 203–254;
       those without counterparts in the ISO range 33–126 are discussed in the next subsection.

       All of the following characters map to glyphs as you would expect.

                      ┌──────────────────────────────────────────────────────────┐
                      │! # $ % & ( ) * + , . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ │
                      │A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ ] _ │
                      │a b c d e f g h i j k l m n o p q r s t u v w x y z { | } │
--

Glyph tables

       In this section, groff's glyph name repertoire is presented in tabular form.  The meanings
       of the columns are as follows.

       Output  shows the glyph as it appears on the device used to render this document; although
               it  can  have  a notably different shape on other devices (and is subject to user-
               directed translation and replacement), groff attempts  reasonable  equivalency  on
               all output devices.

       Input   shows  the groff character (ordinary or special) that normally produces the glyph.
               Some code points have multiple glyph names.

       Unicode is the code point notation for the glyph or combining glyph sequence as  described
               in  subsection  “Special  character  escape  forms”  above.  It corresponds to the
               standard notation for  Unicode  short  identifiers  such  that  groff's  unnnn  is
               equivalent to Unicode's U+nnnn.

       Notes   describes  the  glyph,  elucidating  the  mnemonic  value  of the glyph name where
               possible.

               A plus sign “+” indicates that the glyph name appears in  the  AT&T  troff  user's
               manual,  CSTR  #54  (1992 revision).  When using the AT&T special character syntax
               \(xx, widespread portability can be expected from such names.

               Entries marked with “***”  denote  glyphs  used  for  mathematical  purposes.   On
               typesetting  devices,  such  glyphs  are  typically drawn from a special font (see
               groff_font(5)).  Often, such glyphs lack  bold  or  italic  style  forms  or  have
               metrics  that look incongruous in ordinary prose.  A few which are not uncommon in
               running text have “text variants”, which  should  work  better  in  that  context.
               Conversely,  a  handful  of glyphs that are normally drawn from a text font may be
               required in mathematical equations.  Both sets of  exceptions  are  noted  in  the
               tables where they appear (“Logical symbols” and “Mathematical symbols”).

   Basic Latin
       Apart  from  basic  Latin  characters  with  special  mappings,  described  in  subsection
       “Fundamental character set” above, a few others in that range have special character glyph
       names.   These  were  defined  for ease of input on non-U.S. keyboards lacking keycaps for
       them, or for symmetry with other special character glyph names serving a similar purpose.

       The vertical  bar  is  overloaded;  the  \[ba]  and  \[or]  escape  sequences  may  render
       differently.   See  subsection  “Mathematical  symbols”  below for special variants of the
       plus, minus, and equals signs normally drawn from this range.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       "        \[dq]   u0022     neutral double quote
       #        \[sh]   u0023     number sign
       $        \[Do]   u0024     dollar sign
       '        \[aq]   u0027     apostrophe, neutral single quote
       /        \[sl]   u002F     slash, solidus +
       @        \[at]   u0040     at sign
       [        \[lB]   u005B     left square bracket
       \        \[rs]   u005C     reverse solidus
       ]        \[rB]   u005D     right square bracket
       ^        \[ha]   u005E     circumflex, caret, “hat”
       {        \[lC]   u007B     left brace
       |        |       u007C     bar
       |        \[ba]   u007C     bar
       |        \[or]   u007C     bitwise or +
       }        \[rC]   u007D     right brace
       ~        \[ti]   u007E     tilde

   Supplementary Latin letters
       Historically, \[ss] could be  considered  a  ligature  of  “sz”.   An  uppercase  form  is
       available  as  \[u1E9E],  but  in the German language it is of specialized use; ß does not
       normally uppercase-transform to it, but rather to “SS”.  “Lowercase f with hook”  is  also
       used as a function symbol; see subsection “Mathematical symbols” below.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       Ð        \[-D]   u00D0     uppercase eth
       ð        \[Sd]   u00F0     lowercase eth
       Þ        \[TP]   u00DE     uppercase thorn
       þ        \[Tp]   u00FE     lowercase thorn
       ß        \[ss]   u00DF     lowercase sharp s
       ı        \[.i]   u0131     i without tittle
       ȷ        \[.j]   u0237     j without tittle
       ƒ        \[Fn]   u0192     lowercase f with hook, function
       Ł        \[/L]   u0141     L with stroke
       ł        \[/l]   u0142     l with stroke
       Ø        \[/O]   u00D8     O with stroke
       ø        \[/o]   u00F8     o with stroke

   Ligatures and digraphs
       Output   Input   Unicode           Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ff       \[ff]   u0066_0066        ff ligature +
       fi       \[fi]   u0066_0069        fi ligature +
       fl       \[fl]   u0066_006C        fl ligature +
       ffi      \[Fi]   u0066_0066_0069   ffi ligature +
       ffl      \[Fl]   u0066_0066_006C   ffl ligature +
       Æ        \[AE]   u00C6             AE ligature
       æ        \[ae]   u00E6             ae ligature
       Π       \[OE]   u0152             OE ligature
       œ        \[oe]   u0153             oe ligature
       IJ        \[IJ]   u0132             IJ digraph
       ij        \[ij]   u0133             ij digraph

   Accents
       Normally,  the  formatting  of  a  special  character  advances the drawing position as an
       ordinary character does.  groff's composite request  designates  a  special  character  as
       combining.   The  composite.tmac  macro file, loaded automatically by the default troffrc,
       maps the following special characters to the combining characters shown below.   The  non-
       combining code point in parentheses is used when the special character occurs in isolation
       (compare “caf\[e aa]” and “caf\[aa]e”).

       Output   Input   Unicode         Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ˝        \[a"]   u030B (u02DD)   double acute accent
       ¯        \[a-]   u0304 (u00AF)   macron accent

       ˙        \[a.]   u0307 (u02D9)   dot accent
       ^        \[a^]   u0302 (u005E)   circumflex accent
       ´        \[aa]   u0301 (u00B4)   acute accent +
       `        \[ga]   u0300 (u0060)   grave accent +
       ˘        \[ab]   u0306 (u02D8)   breve accent
       ¸        \[ac]   u0327 (u00B8)   cedilla accent
       ¨        \[ad]   u0308 (u00A8)   dieresis accent
       ˇ        \[ah]   u030C (u02C7)   caron accent
       ˚        \[ao]   u030A (u02DA)   ring accent
       ~        \[a~]   u0303 (u007E)   tilde accent
       ˛        \[ho]   u0328 (u02DB)   hook accent

   Accented characters
       All of these glyphs can be composed using combining glyph names as described in subsection
       “Special character escape forms” above; the names below are short aliases for convenience.

       Output   Input   Unicode      Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       Á        \['A]   u0041_0301   A acute
       Ć        \['C]   u0043_0301   C acute
       É        \['E]   u0045_0301   E acute
       Í        \['I]   u0049_0301   I acute
       Ó        \['O]   u004F_0301   O acute
       Ú        \['U]   u0055_0301   U acute
       Ý        \['Y]   u0059_0301   Y acute
       á        \['a]   u0061_0301   a acute
       ć        \['c]   u0063_0301   c acute
       é        \['e]   u0065_0301   e acute
       í        \['i]   u0069_0301   i acute
       ó        \['o]   u006F_0301   o acute
       ú        \['u]   u0075_0301   u acute
       ý        \['y]   u0079_0301   y acute

       Ä        \[:A]   u0041_0308   A dieresis
       Ë        \[:E]   u0045_0308   E dieresis
       Ï        \[:I]   u0049_0308   I dieresis
       Ö        \[:O]   u004F_0308   O dieresis
       Ü        \[:U]   u0055_0308   U dieresis
       Ÿ        \[:Y]   u0059_0308   Y dieresis
       ä        \[:a]   u0061_0308   a dieresis
       ë        \[:e]   u0065_0308   e dieresis
       ï        \[:i]   u0069_0308   i dieresis
       ö        \[:o]   u006F_0308   o dieresis
       ü        \[:u]   u0075_0308   u dieresis
       ÿ        \[:y]   u0079_0308   y dieresis

       Â        \[^A]   u0041_0302   A circumflex
       Ê        \[^E]   u0045_0302   E circumflex
       Î        \[^I]   u0049_0302   I circumflex
       Ô        \[^O]   u004F_0302   O circumflex
       Û        \[^U]   u0055_0302   U circumflex
       â        \[^a]   u0061_0302   a circumflex
       ê        \[^e]   u0065_0302   e circumflex
       î        \[^i]   u0069_0302   i circumflex
       ô        \[^o]   u006F_0302   o circumflex
       û        \[^u]   u0075_0302   u circumflex

       À        \[`A]   u0041_0300   A grave
       È        \[`E]   u0045_0300   E grave
       Ì        \[`I]   u0049_0300   I grave
       Ò        \[`O]   u004F_0300   O grave
       Ù        \[`U]   u0055_0300   U grave
       à        \[`a]   u0061_0300   a grave
       è        \[`e]   u0065_0300   e grave
       ì        \[`i]   u0069_0300   i grave
       ò        \[`o]   u006F_0300   o grave
       ù        \[`u]   u0075_0300   u grave

       Ã        \[~A]   u0041_0303   A tilde

       Ñ        \[~N]   u004E_0303   N tilde
       Õ        \[~O]   u004F_0303   O tilde
       ã        \[~a]   u0061_0303   a tilde
       ñ        \[~n]   u006E_0303   n tilde
       õ        \[~o]   u006F_0303   o tilde

       Š        \[vS]   u0053_030C   S caron
       š        \[vs]   u0073_030C   s caron
       Ž        \[vZ]   u005A_030C   Z caron
       ž        \[vz]   u007A_030C   z caron

       Ç        \[,C]   u0043_0327   C cedilla
       ç        \[,c]   u0063_0327   c cedilla

       Å        \[oA]   u0041_030A   A ring
       å        \[oa]   u0061_030A   a ring

   Quotation marks
       The  neutral  double  quote,  often useful when documenting programming languages, is also
       available as a  special  character  for  convenient  embedding  in  macro  arguments;  see
       subsection “Fundamental character set” above.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       „        \[Bq]   u201E     low double comma quote
       ‚        \[bq]   u201A     low single comma quote
       “        \[lq]   u201C     left double quote
       ”        \[rq]   u201D     right double quote
       ‘        \[oq]   u2018     single opening (left) quote
       ’        \[cq]   u2019     single closing (right) quote
       '        \[aq]   u0027     apostrophe, neutral single quote
       "        "       u0022     neutral double quote
       "        \[dq]   u0022     neutral double quote
       «        \[Fo]   u00AB     left double chevron
       »        \[Fc]   u00BB     right double chevron
       ‹        \[fo]   u2039     left single chevron
       ›        \[fc]   u203A     right single chevron

   Punctuation
       The  Unicode  name  for U+00B7 is “middle dot”, which is unfortunately confusable with the
       groff mnemonic for the visually similar but semantically distinct multiplication dot;  see
       subsection “Mathematical symbols” below.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ¡        \[r!]   u00A1     inverted exclamation mark
       ¿        \[r?]   u00BF     inverted question mark
       ·        \[pc]   u00B7     centered period
       —        \[em]   u2014     em-dash +
       –        \[en]   u2013     en-dash
       ‐        \[hy]   u2010     hyphen +

   Brackets
       On  typesetting  devices,  the bracket extensions are font-invariant glyphs; that is, they
       are rendered the same way regardless  of  font  (with  a  drawing  escape  sequence).   On
       terminals,  they  are  not  font-invariant;  groff  maps them rather arbitrarily to U+23AA
       (“curly bracket extension”).  In AT&T troff, only one glyph was  available  to  vertically
       extend brackets, braces, and parentheses: \(bv.

       Not all devices supply bracket pieces that can be piled up with \b due to the restrictions
       of the escape's piling algorithm.  A general solution to build brackets out of  pieces  is
       the following macro:
              .\" Make a pile centered vertically 0.5em above the baseline.
              .\" The first argument is placed at the top.
              .\" The pile is returned in string 'pile'.
              .eo
              .de pile-make
              .  nr pile-wd 0
              .  nr pile-ht 0
              .  ds pile-args
              .
              .  nr pile-# \n[.$]
              .  while \n[pile-#] \{\
              .    nr pile-wd (\n[pile-wd] >? \w'\$[\n[pile-#]]')
              .    nr pile-ht +(\n[rst] - \n[rsb])
              .    as pile-args \v'\n[rsb]u'\"
              .    as pile-args \Z'\$[\n[pile-#]]'\"
              .    as pile-args \v'-\n[rst]u'\"
              .    nr pile-# -1
              .  \}
              .
              .  ds pile \v'(-0.5m + (\n[pile-ht]u / 2u))'\"
              .  as pile \*[pile-args]\"
              .  as pile \v'((\n[pile-ht]u / 2u) + 0.5m)'\"
              .  as pile \h'\n[pile-wd]u'\"
              ..
              .ec

       Another  complication  is the fact that some glyphs which represent bracket pieces in AT&T
       troff can be used for other mathematical symbols as well, for example \(lf and \(rf, which
       provide  the  floor  operator.  Some output devices, such as dvi, don't unify such glyphs.
       For this reason, the glyphs \[lf], \[rf], \[lc], and \[rc] are not unified  with  similar-
       looking  bracket  pieces.  In groff, only glyphs with long names are guaranteed to pile up
       correctly for all devices—provided those glyphs are available.

       Output   Input               Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       [        [                   u005B     left square bracket
       [        \[lB]               u005B     left square bracket
       ]        ]                   u005D     right square bracket
       ]        \[rB]               u005D     right square bracket
       {        {                   u007B     left brace
       {        \[lC]               u007B     left brace
       }        }                   u007D     right brace
       }        \[rC]               u007D     right brace
       ⟨        \[la]               u27E8     left angle bracket
       ⟩        \[ra]               u27E9     right angle bracket
       ⎪        \[bv]               u23AA     brace vertical extension + ***
       ⎪        \[braceex]          u23AA     brace vertical extension

       ⎡        \[bracketlefttp]    u23A1     left square bracket top
       ⎢        \[bracketleftex]    u23A2     left square bracket extension
       ⎣        \[bracketleftbt]    u23A3     left square bracket bottom

       ⎤        \[bracketrighttp]   u23A4     right square bracket top
       ⎥        \[bracketrightex]   u23A5     right square bracket extension
       ⎦        \[bracketrightbt]   u23A6     right square bracket bottom

       ⎧        \[lt]               u23A7     left brace top +
       ⎨        \[lk]               u23A8     left brace middle +
       ⎩        \[lb]               u23A9     left brace bottom +
       ⎧        \[bracelefttp]      u23A7     left brace top
       ⎨        \[braceleftmid]     u23A8     left brace middle
       ⎩        \[braceleftbt]      u23A9     left brace bottom
       ⎪        \[braceleftex]      u23AA     left brace extension

       ⎫        \[rt]               u23AB     right brace top +
       ⎬        \[rk]               u23AC     right brace middle +
       ⎭        \[rb]               u23AD     right brace bottom +
       ⎫        \[bracerighttp]     u23AB     right brace top
       ⎬        \[bracerightmid]    u23AC     right brace middle
       ⎭        \[bracerightbt]     u23AD     right brace bottom
       ⎪        \[bracerightex]     u23AA     right brace extension

       ⎛        \[parenlefttp]      u239B     left parenthesis top
       ⎜        \[parenleftex]      u239C     left parenthesis extension
       ⎝        \[parenleftbt]      u239D     left parenthesis bottom
       ⎞        \[parenrighttp]     u239E     right parenthesis top
       ⎟        \[parenrightex]     u239F     right parenthesis extension

       ⎠        \[parenrightbt]     u23A0     right parenthesis bottom

   Arrows
       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ←        \[<-]   u2190     horizontal arrow left +
       →        \[->]   u2192     horizontal arrow right +
       ↔        \[<>]   u2194     bidirectional horizontal arrow
       ↓        \[da]   u2193     vertical arrow down +
       ↑        \[ua]   u2191     vertical arrow up +
       ↕        \[va]   u2195     bidirectional vertical arrow
       ⇐        \[lA]   u21D0     horizontal double arrow left
       ⇒        \[rA]   u21D2     horizontal double arrow right
       ⇔        \[hA]   u21D4     bidirectional horizontal double arrow
       ⇓        \[dA]   u21D3     vertical double arrow down
       ⇑        \[uA]   u21D1     vertical double arrow up
       ⇕        \[vA]   u21D5     bidirectional vertical double arrow
       ⎯        \[an]   u23AF     horizontal arrow extension

   Rules and lines
       On typesetting devices, the font-invariant glyphs (see subsection “Brackets” above) \[br],
       \[ul], and \[rn] form corners when adjacent; they can be used to build boxes.  On terminal
       devices, they are mapped as shown in the table.  The Unicode-derived names of these  three
       glyphs are approximations.

       The  input character _ always accesses the underscore glyph in a font; \[ul], by contrast,
       may be font-invariant on typesetting devices.

       The baseline rule \[ru] is a font-invariant glyph, namely a rule of one-half em.

       In AT&T troff, \[rn] also served as a one en extension of the square root  symbol.   groff
       favors \[radicalex] for this purpose; see subsection “Mathematical symbols” below.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       |        |       u007C     bar
       |        \[ba]   u007C     bar
       │        \[br]   u2502     box rule +
       _        _       u005F     underscore, low line +
       _        \[ul]   ---       underrule +
       ‾        \[rn]   u203E     overline +
       _        \[ru]   ---       baseline rule +
       ¦        \[bb]   u00A6     broken bar
       /        /       u002F     slash, solidus +
       /        \[sl]   u002F     slash, solidus +
       \        \[rs]   u005C     reverse solidus

   Text markers
       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ○        \[ci]   u25CB     circle +
       •        \[bu]   u2022     bullet +
       †        \[dg]   u2020     dagger +
       ‡        \[dd]   u2021     double dagger +
       ◊        \[lz]   u25CA     lozenge, diamond
       □        \[sq]   u25A1     square +
       ¶        \[ps]   u00B6     pilcrow sign
       §        \[sc]   u00A7     section sign +
       ☜        \[lh]   u261C     hand pointing left +
       ☞        \[rh]   u261E     hand pointing right +
       @        @       u0040     at sign
       @        \[at]   u0040     at sign
       #        #       u0023     number sign
       #        \[sh]   u0023     number sign
       ↵        \[CR]   u21B5     carriage return
       ✓        \[OK]   u2713     check mark

   Legal symbols
       The Bell System logo is not supported in groff.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ©        \[co]   u00A9     copyright sign +
       ®        \[rg]   u00AE     registered sign +
       ™        \[tm]   u2122     trade mark sign
                \[bs]   ---       Bell System logo +

   Currency symbols
       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       $        $       u0024     dollar sign
       $        \[Do]   u0024     dollar sign
       ¢        \[ct]   u00A2     cent sign +
       €        \[eu]   u20AC     Euro sign
       €        \[Eu]   u20AC     variant Euro sign
       ¥        \[Ye]   u00A5     yen sign
       £        \[Po]   u00A3     pound sign
       ¤        \[Cs]   u00A4     currency sign

   Units
       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       °        \[de]   u00B0     degree sign +
       ‰        \[%0]   u2030     per thousand, per mille sign
       ′        \[fm]   u2032     arc minute sign, foot mark +
       ″        \[sd]   u2033     arc second sign
       µ        \[mc]   u00B5     micro sign
       ª        \[Of]   u00AA     feminine ordinal indicator
       º        \[Om]   u00BA     masculine ordinal indicator

   Logical symbols
       The  variants  of the not sign may differ in appearance or spacing depending on the device
       and font selected.  Unicode does not encode a discrete “bitwise or” sign:  on  typesetting
       devices,  it  is  drawn  shorter  than the bar, about the same height as a capital letter.
       Terminal devices unify \[ba] and \[or].

       Output   Input    Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ∧        \[AN]    u2227     logical and
       ∨        \[OR]    u2228     logical or
       ¬        \[no]    u00AC     logical not + ***
       ¬        \[tno]   u00AC     text variant of \[no]
       ∃        \[te]    u2203     there exists
       ∀        \[fa]    u2200     for all
       ∋        \[st]    u220B     such that
       ∴        \[3d]    u2234     therefore
       ∴        \[tf]    u2234     therefore
       |        |        u007C     bar
       |        \[or]    u007C     bitwise or +

   Mathematical symbols
       \[Fn] also appears in subsection “Supplementary Latin letters”  above.   Observe  the  two
       varieties  of  the plus-minus, multiplication, and division signs; \[+-], \[mu], and \[di]
       are normally drawn from the special font, but have text font variants.  Also be  aware  of
       three  glyphs  available in special font variants that are normally drawn from text fonts:
       the plus, minus, and equals signs.  These variants may differ  in  appearance  or  spacing
       depending on the device and font selected.

       In AT&T troff, \(rn (“root en extender”) served as the horizontal extension of the radical
       (square root) sign, \(sr, and was drawn at the maximum height of the  typeface's  bounding
       box;  this  enabled  the special character to double as an overline (see subsection “Rules
       and lines” above).  A contemporary font's  radical  sign  might  not  ascend  to  such  an
       extreme.   In  groff, you can instead use \[radicalex] to continue the radical sign \[sr];
       these special characters are intended for use with text fonts.  \[sqrt] and \[sqrtex]  are
       their counterparts with mathematical spacing.

       Output   Input          Unicode      Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ½        \[12]          u00BD        one half symbol +

       ¼        \[14]          u00BC        one quarter symbol +
       ¾        \[34]          u00BE        three quarters symbol +
       ⅛        \[18]          u215B        one eighth symbol
       ⅜        \[38]          u215C        three eighths symbol
       ⅝        \[58]          u215D        five eighths symbol
       ⅞        \[78]          u215E        seven eighths symbol
       ¹        \[S1]          u00B9        superscript one
       ²        \[S2]          u00B2        superscript two
       ³        \[S3]          u00B3        superscript three

       +        +              u002B        plus
       +        \[pl]          u002B        special variant of plus + ***
       -        \[-]           u002D        minus
       −        \[mi]          u2212        special variant of minus + ***
       ∓        \[-+]          u2213        minus-plus
       ±        \[+-]          u00B1        plus-minus + ***
       ±        \[t+-]         u00B1        text variant of \[+-]
       ⋅        \[md]          u22C5        multiplication dot
       ×        \[mu]          u00D7        multiplication sign + ***
       ×        \[tmu]         u00D7        text variant of \[mu]
       ⊗        \[c*]          u2297        circled times
       ⊕        \[c+]          u2295        circled plus
       ÷        \[di]          u00F7        division sign + ***
       ÷        \[tdi]         u00F7        text variant of \[di]
       ⁄        \[f/]          u2044        fraction slash
       *        *              u002A        asterisk
       ∗        \[**]          u2217        mathematical asterisk +

       ≤        \[<=]          u2264        less than or equal to +
       ≥        \[>=]          u2265        greater than or equal to +
       ≪        \[<<]          u226A        much less than
       ≫        \[>>]          u226B        much greater than
       =        =              u003D        equals
       =        \[eq]          u003D        special variant of equals + ***
       ≠        \[!=]          u003D_0338   not equals +
       ≡        \[==]          u2261        equivalent +
       ≢        \[ne]          u2261_0338   not equivalent
       ≅        \[=~]          u2245        approximately equal to
       ≃        \[|=]          u2243        asymptotically equal to +
       ~        \[ti]          u007E        tilde +
       ∼        \[ap]          u223C        similar to, tilde operator +
       ≈        \[~~]          u2248        almost equal to
       ≈        \[~=]          u2248        almost equal to
       ∝        \[pt]          u221D        proportional to +

       ∅        \[es]          u2205        empty set +
       ∈        \[mo]          u2208        element of a set +
       ∉        \[nm]          u2208_0338   not element of set
       ⊂        \[sb]          u2282        proper subset +
       ⊄        \[nb]          u2282_0338   not subset
       ⊃        \[sp]          u2283        proper superset +
       ⊅        \[nc]          u2283_0338   not superset
       ⊆        \[ib]          u2286        subset or equal +
       ⊇        \[ip]          u2287        superset or equal +
       ∩        \[ca]          u2229        intersection, cap +
       ∪        \[cu]          u222A        union, cup +

       ∠        \[/_]          u2220        angle
       ⊥        \[pp]          u22A5        perpendicular
       ∫        \[is]          u222B        integral +
       ∫        \[integral]    u222B        integral ***
       ∑        \[sum]         u2211        summation ***
       ∏        \[product]     u220F        product ***
       ∐        \[coproduct]   u2210        coproduct ***
       ∇        \[gr]          u2207        gradient +
       √        \[sr]          u221A        radical sign, square root +
       ‾        \[rn]          u203E        overline +
                \[radicalex]   ---          radical extension
       √        \[sqrt]        u221A        radical sign, square root ***

                \[sqrtex]      ---          radical extension ***

       ⌈        \[lc]          u2308        left ceiling +
       ⌉        \[rc]          u2309        right ceiling +
       ⌊        \[lf]          u230A        left floor +
       ⌋        \[rf]          u230B        right floor +

       ∞        \[if]          u221E        infinity +
       ℵ        \[Ah]          u2135        aleph symbol
       ƒ        \[Fn]          u0192        lowercase f with hook, function
       ℑ        \[Im]          u2111        blackletter I, imaginary part
       ℜ        \[Re]          u211C        blackletter R, real part
       ℘        \[wp]          u2118        Weierstrass p
       ∂        \[pd]          u2202        partial differential
       ℏ        \[-h]          u210F        h bar
       ℏ        \[hbar]        u210F        h bar

   Greek glyphs
       These  glyphs  are  intended  for  technical use, not for typesetting Greek language text;
       normally, the uppercase letters have upright shape, and the lowercase ones are slanted.

       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       Α        \[*A]   u0391     uppercase alpha +
       Β        \[*B]   u0392     uppercase beta +
       Γ        \[*G]   u0393     uppercase gamma +
       Δ        \[*D]   u0394     uppercase delta +
       Ε        \[*E]   u0395     uppercase epsilon +
       Ζ        \[*Z]   u0396     uppercase zeta +
       Η        \[*Y]   u0397     uppercase eta +
       Θ        \[*H]   u0398     uppercase theta +
       Ι        \[*I]   u0399     uppercase iota +
       Κ        \[*K]   u039A     uppercase kappa +
       Λ        \[*L]   u039B     uppercase lambda +
       Μ        \[*M]   u039C     uppercase mu +
       Ν        \[*N]   u039D     uppercase nu +
       Ξ        \[*C]   u039E     uppercase xi +
       Ο        \[*O]   u039F     uppercase omicron +
       Π        \[*P]   u03A0     uppercase pi +
       Ρ        \[*R]   u03A1     uppercase rho +
       Σ        \[*S]   u03A3     uppercase sigma +
       Τ        \[*T]   u03A4     uppercase tau +
       Υ        \[*U]   u03A5     uppercase upsilon +
       Φ        \[*F]   u03A6     uppercase phi +
       Χ        \[*X]   u03A7     uppercase chi +
       Ψ        \[*Q]   u03A8     uppercase psi +
       Ω        \[*W]   u03A9     uppercase omega +

       α        \[*a]   u03B1     lowercase alpha +
       β        \[*b]   u03B2     lowercase beta +
       γ        \[*g]   u03B3     lowercase gamma +
       δ        \[*d]   u03B4     lowercase delta +
       ε        \[*e]   u03B5     lowercase epsilon +
       ζ        \[*z]   u03B6     lowercase zeta +
       η        \[*y]   u03B7     lowercase eta +
       θ        \[*h]   u03B8     lowercase theta +
       ι        \[*i]   u03B9     lowercase iota +
       κ        \[*k]   u03BA     lowercase kappa +
       λ        \[*l]   u03BB     lowercase lambda +
       μ        \[*m]   u03BC     lowercase mu +
       ν        \[*n]   u03BD     lowercase nu +
       ξ        \[*c]   u03BE     lowercase xi +
       ο        \[*o]   u03BF     lowercase omicron +
       π        \[*p]   u03C0     lowercase pi +
       ρ        \[*r]   u03C1     lowercase rho +
       σ        \[*s]   u03C3     lowercase sigma +
       τ        \[*t]   u03C4     lowercase tau +
       υ        \[*u]   u03C5     lowercase upsilon +
       ϕ        \[*f]   u03D5     lowercase phi +

       χ        \[*x]   u03C7     lowercase chi +
       ψ        \[*q]   u03C8     lowercase psi +
       ω        \[*w]   u03C9     lowercase omega +

       ϵ        \[+e]   u03F5     variant epsilon (lunate)
       ϑ        \[+h]   u03D1     variant theta (cursive form)
       ϖ        \[+p]   u03D6     variant pi (similar to omega)
       φ        \[+f]   u03C6     variant phi (curly shape)
       ς        \[ts]   u03C2     terminal lowercase sigma +

   Playing card symbols
       Output   Input   Unicode   Notes
       ───────────────────────────────────────────────────────────────────────────────────────────
       ♣        \[CL]   u2663     solid club suit
       ♠        \[SP]   u2660     solid spade suit
       ♥        \[HE]   u2665     solid heart suit
       ♦        \[DI]   u2666     solid diamond suit

History

       A consideration of the typefaces originally available to AT&T nroff and troff  illuminates
       many  conventions  that  one  might  regard  as idiosyncratic fifty years afterward.  (See
       section “History” of roff(7) for more context.)  The face used by the  Teletype  Model  37
       terminals  of the Murray Hill Unix Room was based on ASCII, but assigned multiple meanings
       to several code points, as suggested by  that  standard.   Decimal  34  (")  served  as  a
       dieresis  accent  and  neutral  double  quotation mark; decimal 39 (') as an acute accent,
       apostrophe, and closing (right) single quotation mark; decimal 45 (-) as a  hyphen  and  a
       minus  sign;  decimal  94  (^) as a circumflex accent and caret; decimal 96 (`) as a grave
       accent and opening (left) single quotation mark; and decimal 126 (~) as a tilde accent and
       (with  a  half-line  motion) swung dash.  The Model 37 bore an optional extended character
       set offering upright Greek letters and several mathematical symbols; these were documented
       as early as the kbd(VII) man page of the (First Edition) Unix Programmer's Manual.

       At  the  time  Graphic  Systems  delivered  the  C/A/T  phototypesetter to AT&T, the ASCII
       character set was not considered a standard basis for a glyph  repertoire  by  traditional
       typographers.   In the stock Times roman, italic, and bold styles available, several ASCII
       characters were not present at all, nor was most of the Teletype's extended character set.
       AT&T commissioned a “special” font to ensure no loss of repertoire.

       A  representation of the coverage of the C/A/T's text fonts follows.  The glyph resembling
       an underscore is a baseline rule, and that resembling a vertical line is a box  rule.   In
       italics,  the  box  rule  was not slanted.  We also observe that the hyphen and minus sign
       were already “de-unified” by the fonts provided; a decision whither to map  an  input  “-”
       therefore had to be taken.

                         ┌────────────────────────────────────────────────────┐
                         │A B C D E F G H I J K L M N O P Q R S T U V W X Y Z │
                         │a b c d e f g h i j k l m n o p q r s t u v w x y z │
                         │0 1 2 3 4 5 6 7 8 9 fi fl ffi ffl                   │
                         │! $ % & ( ) ‘ ’ * + - . , / : ; = ? [ ] │           │
                         │• □ — ‐ _ ¼ ½ ¾ ° † ′ ¢ ® ©                         │
                         └────────────────────────────────────────────────────┘
       The  special  font  supplied the missing ASCII and Teletype extended glyphs, among several
       others.  The  plus,  minus,  and  equals  signs  appeared  in  the  special  font  despite
       availability  in  text  fonts  “to insulate the appearance of equations from the choice of
       standard [read: text] fonts”—a priority since troff was turned to the task of mathematical
       typesetting as soon as it was developed.

       We  note  that AT&T took the opportunity to de-unify the apostrophe/right single quotation
       mark from the acute  accent  (a  choice  ISO  later  duplicated  in  its  8859  series  of
       standards).  A slash intended to be mirror-symmetric with the backslash was also included,
       as was the Bell System logo; we do not attempt to depict the latter.

                       ┌─────────────────────────────────────────────────────────┐
                       │α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ σ ς τ υ ϕ χ ψ ω        │
                       │Γ Δ Θ Λ Ξ Π Σ Υ Φ Ψ Ω                                    │
                       │" ´ \ ^ _ ` ~ / < > { } # @ + − = ∗                      │
                       │≥ ≤ ≡ ≈ ∼ ≠ ↑ ↓ ← → × ÷ ± ∞ ∂ ∇ ¬ ∫ ∝ √  ∪ ∩ ⊂ ⊃ ⊆ ⊇ ∅ ∈ │
                       │§ ‡ ☜ ☞ | ○ ⎧ ⎩ ⎫ ⎭ ⎨ ⎬ ⎪ ⌊ ⌋ ⌈ ⌉                        │
                       └─────────────────────────────────────────────────────────┘
       One ASCII character as rendered by the Model 37 was  apparently  abandoned.   That  device
       printed decimal 124 (|) as a broken vertical line, like Unicode U+00A6 (¦).  No equivalent
       was available on the C/A/T; the box rule \[br], brace vertical extension \[bv],  and  “or”
       operator \[or] were used as contextually appropriate.

       Devices  supported  by  AT&T  device-independent troff exhibited some differences in glyph
       detail.  For example, on the Autologic  APS-5  phototypesetter,  the  square  \(sq  became
       filled in the Times bold face.

Files

       The files below are loaded automatically by the default troffrc.

       /usr/share/groff/1.23.0/tmac/composite.tmac
              assigns  alternate  mappings for identifiers after the first in a composite special
              character escape sequence.  See subsection “Accents” above.

       /usr/share/groff/1.23.0/tmac/fallbacks.tmac
              defines fallback mappings for Unicode  code  points  such  as  the  increment  sign
              (U+2206) and upper- and lowercase Roman numerals.

Authors

       This  document  was  written  by  James  Clark  ⟨jjc@jclark.com⟩, with additions by Werner
       Lemberg ⟨wl@gnu.org⟩ and  Bernd  Warken  ⟨groff-bernd.warken-72@web.de⟩,  revised  to  use
       tbl(1)  by Eric S. Raymond ⟨esr@thyrsus.com⟩, and largely rewritten by G. Branden Robinson
       ⟨g.branden.robinson@gmail.com⟩.

See also

       Groff: The GNU Implementation of troff, by Trent A. Fisher  and  Werner  Lemberg,  is  the
       primary  groff manual.  Section “Using Symbols” may be of particular note.  You can browse
       it interactively with “info '(groff) Using Symbols'”.

       “An extension to the troff character set for  Europe”,  E.G.  Keizer,  K.J.  Simonsen,  J.
       Akkerhuis; EUUG Newsletter, Volume 9, No. 2, Summer 1989

       The Unicode Standard ⟨http://www.unicode.org⟩

       “7-bit  Character  Sets”  ⟨https://www.aivosto.com/articles/charsets-7bit.html⟩  by Tuomas
       Salste documents the inherent ambiguity and configurable code points of the ASCII encoding
       standard.

       “Nroff/Troff  User's  Manual” by Joseph F. Ossanna, 1976, AT&T Bell Laboratories Computing
       Science Technical Report No. 54, features  two  tables  that  throw  light  on  the  glyph
       repertoire  available  to  “typesetter roff” when it was first written.  Be careful of re-
       typeset versions of this document that  can  be  found  on  the  Internet.   Some  do  not
       accurately  represent  the  original document: several glyphs are obviously missing.  More
       subtly, lowercase Greek letters are rendered upright, not slanted as they appeared in  the
       C/A/T's special font and as expected by troff users.

       groff_rfc1345(7)  describes  an  alternative  set  of special character glyph names, which
       extends and in some cases overrides the definitions listed above.

       groff(1), troff(1), groff(7)