[groff] 12/23: doc/groff.texi: Improve Texinfo usage.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 6ab752cea24ea6a7e6d8f722ee1ebe3829383660
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Fri Aug 11 19:14:47 2023 -0500

    doc/groff.texi: Improve Texinfo usage.
    
    Use more specific Texinfo command @command for command programs, rather
    than @code, to mark up "gtroff", which is only ever a command.
    
    This update reveals some category errors in the discussion, largely in
    material I haven't revised yet.
---
 doc/groff.texi | 237 +++++++++++++++++++++++++++++----------------------------
 1 file changed, 121 insertions(+), 116 deletions(-)

diff --git a/doc/groff.texi b/doc/groff.texi
index 7aff8c006..df4eff298 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -4938,8 +4938,9 @@ Names containing only uppercase letters and digits.
 
 @node GNU troff Reference, File Formats, Major Macro Packages, Top
 @chapter GNU @code{troff} Reference
-@cindex reference, @code{gtroff}
-@cindex @code{gtroff}, reference
+@cindex reference, @command{gtroff}
+@cindex @command{gtroff}, reference
+@cindex @command{troff}, GNU, reference
 
 This chapter covers @emph{all} of the facilities of the GNU
 @code{troff} formatting engine.  Users of macro packages may skip it if
@@ -9622,8 +9623,8 @@ file @file{tty.tmac}, which is loaded by the startup file
 
 @cindex dimensions, line
 @cindex line dimensions
-The following drawing shows the dimensions that @code{gtroff} uses for
-placing a line of output onto the page.  They are labeled with the
+The following drawing shows the dimensions that @command{gtroff} uses
+for placing a line of output onto the page.  They are labeled with the
 request that manipulates each dimension.
 
 @Example
@@ -9738,7 +9739,7 @@ the previous value before the last call to @code{in}.  
The default
 scaling unit is @samp{m}.
 
 If a negative indentation value is specified (which is not allowed),
-@code{gtroff} emits a warning in category @samp{range} and sets the
+@command{gtroff} emits a warning in category @samp{range} and sets the
 indentation to zero.
 
 The effect of @code{in} is delayed until a partially collected line (if
@@ -9763,7 +9764,7 @@ environment (@pxref{Environments}).  The default scaling 
unit is
 @samp{m}.  A call of @code{ti} without an argument is ignored.
 
 If the total indentation value is negative (which is not allowed),
-@code{gtroff} emits a warning in category @samp{range} and sets the
+@command{gtroff} emits a warning in category @samp{range} and sets the
 temporary indentation to zero.  `Total indentation' is either
 @var{offset} if specified as an absolute value, or the temporary plus
 normal indentation, if @var{offset} is given as a relative value.
@@ -9792,9 +9793,10 @@ collected line (if it exists) is output.  The default 
scaling unit is
 
 If @code{ll} is called without an argument, the line length is reset to
 the previous value before the last call to @code{ll}.  If a negative
-line length is specified (which is not allowed), @code{gtroff} emits a
-warning in category @samp{range} and sets the line length to zero.  The
-line length is associated with the environment (@pxref{Environments}).
+line length is specified (which is not allowed), @command{gtroff} emits
+a warning in category @samp{range} and sets the line length to zero.
+The line length is associated with the environment
+(@pxref{Environments}).
 
 @cindex line length register (@code{.l})
 The current line length (as set by @code{ll}) can be found in the
@@ -10693,18 +10695,18 @@ horizontal motions in the output.
 @pindex DESC
 @cindex @code{special} request, and glyph search order
 @cindex @code{fspecial} request, and glyph search order
-A @dfn{symbol} is simply a named glyph.  Within @code{gtroff}, all glyph
-names of a particular font are defined in its font file.  If the user
-requests a glyph not available in this font, @code{gtroff} looks up an
-ordered list of @dfn{special fonts}.  By default, the PostScript output
-device supports the two special fonts @samp{SS} (slanted symbols) and
-@samp{S} (symbols) (the former is looked up before the latter).  Other
-output devices use different names for special fonts.  Fonts mounted
-with the @code{fonts} keyword in the @file{DESC} file are globally
-available.  To install additional special fonts locally (i.e., for a
-particular font), use the @code{fspecial} request.
-
-Here are the exact rules how @code{gtroff} searches a given symbol:
+A @dfn{symbol} is simply a named glyph.  Within @command{gtroff}, all
+glyph names of a particular font are defined in its font file.  If the
+user requests a glyph not available in this font, @command{gtroff} looks
+up an ordered list of @dfn{special fonts}.  By default, the PostScript
+output device supports the two special fonts @samp{SS} (slanted symbols)
+and @samp{S} (symbols) (the former is looked up before the latter).
+Other output devices use different names for special fonts.  Fonts
+mounted with the @code{fonts} keyword in the @file{DESC} file are
+globally available.  To install additional special fonts locally (i.e.,
+for a particular font), use the @code{fspecial} request.
+
+GNU @command{troff} searches for a symbol as follows.
 
 @itemize @bullet
 @item
@@ -10764,7 +10766,7 @@ at font position@tie{}1, and @code{BAZ} at 
position@tie{}2.
 We now switch to a new font @code{XXX}, trying to access glyph
 @code{foo} that is assumed to be missing.  There are neither
 font-specific special fonts for @code{XXX} nor any other fonts made
-special with the @code{special} request, so @code{gtroff} starts the
+special with the @code{special} request, so @command{gtroff} starts the
 search for special fonts in the list of already mounted fonts, with
 increasing font positions.  Consequently, it finds @code{BAZ} before
 @code{FOO} even for @code{XXX}, which is not the intended behaviour.
@@ -10791,7 +10793,7 @@ to obtain those available with the DVI device and 
default font
 configuration.@footnote{Not all versions of the @code{man} program
 support the @option{-T} option; use the subsequent example for an
 alternative.}  If you want to use an additional macro package to change
-the fonts used, @code{groff} (or @code{gtroff}) must be run directly.
+the fonts used, @code{groff} (or @command{gtroff}) must be run directly.
 
 @Example
 groff -Tdvi -mec -man groff_char.7 > groff_char.dvi
@@ -11196,20 +11198,20 @@ X
     @result{} Z
 @endExample
 
-The @code{fchar} request defines a fallback glyph: @code{gtroff} only
+The @code{fchar} request defines a fallback glyph: @command{gtroff} only
 checks for glyphs defined with @code{fchar} if it cannot find the glyph
-in the current font.  @code{gtroff} carries out this test before
+in the current font.  @command{gtroff} carries out this test before
 checking special fonts.
 
 @code{fschar} defines a fallback glyph for font@tie{}@var{f}:
-@code{gtroff} checks for glyphs defined with @code{fschar} after the
+@command{gtroff} checks for glyphs defined with @code{fschar} after the
 list of fonts declared as font-specific special fonts with the
 @code{fspecial} request, but before the list of fonts declared as global
 special fonts with the @code{special} request.
 
 Finally, the @code{schar} request defines a global fallback glyph:
-@code{gtroff} checks for glyphs defined with @code{schar} after the list
-of fonts declared as global special fonts with the @code{special}
+@command{gtroff} checks for glyphs defined with @code{schar} after the
+list of fonts declared as global special fonts with the @code{special}
 request, but before the already mounted special fonts.
 
 @xref{Character Classes}.
@@ -11317,13 +11319,13 @@ See the @code{cflags} request in @ref{Using Symbols}, 
for more details.
 @cindex special fonts
 @cindex fonts, special
 
-Special fonts are those that @code{gtroff} searches when it cannot find
-the requested glyph in the current font.  The Symbol font is usually a
-special font.
+Special fonts are those that @command{gtroff} searches when it cannot
+find the requested glyph in the current font.  The Symbol font is
+usually a special font.
 
-@code{gtroff} provides the following two requests to add more special
+@command{gtroff} provides the following two requests to add more special
 fonts.  @xref{Using Symbols}, for a detailed description of the glyph
-searching mechanism in @code{gtroff}.
+searching mechanism in @command{gtroff}.
 
 Usually, only non-TTY devices have special fonts.
 
@@ -11385,7 +11387,7 @@ a single character as an argument) to change the font 
on the fly:
 .mc \H'+5z'x\H'0'
 @endExample
 
-In compatibility mode, @code{gtroff} behaves differently: If an
+In compatibility mode, @command{gtroff} behaves differently: If an
 increment or decrement is used, it is always taken relative to the
 current type size and not relative to the previously selected font
 height.  Thus,
@@ -15863,7 +15865,7 @@ escape sequences.
 @cindex requests for input and output
 @cindex output and input requests
 
-@code{gtroff} has several requests for including files:
+@command{gtroff} has several requests for including files:
 
 @DefreqList {so, file}
 @DefreqListEndx {soquiet, file}
@@ -15918,11 +15920,11 @@ for @code{pso} also.
 @DefreqList {mso, file}
 @DefreqListEndx {msoquiet, file}
 Identical to the @code{so} and @code{soquiet} requests, respectively,
-except that @code{gtroff} searches for the specified @var{file} in the
-same directories as macro files for the @option{-m} command-line option.
-If the file name to be included has the form @file{@var{name}.tmac} and
-it isn't found, these requests try to include @file{tmac.@var{name}} and
-vice versa.
+except that @command{gtroff} searches for the specified @var{file} in
+the same directories as macro files for the @option{-m} command-line
+option.  If the file name to be included has the form
+@file{@var{name}.tmac} and it isn't found, these requests try to include
+@file{tmac.@var{name}} and vice versa.
 @endDefreq
 
 @DefreqList {trf, file}
@@ -15952,7 +15954,7 @@ behaviour is so anomalous that it must be considered a 
bug.
 @cindex invalid characters for @code{trf} request
 While @code{cf} copies the contents of @var{file} completely
 unprocessed, @code{trf} disallows characters such as NUL that are not
-valid @code{gtroff} input characters (@pxref{Identifiers}).
+valid @command{gtroff} input characters (@pxref{Identifiers}).
 
 For @code{cf}, within a diversion, ``completely unprocessed'' means that
 each line of a file to be inserted is handled as if it were preceded by
@@ -15978,8 +15980,9 @@ from becoming part of the diversion 
(@pxref{Diversions}).
 @cindex processing next file (@code{nx})
 @cindex file, processing next (@code{nx})
 @cindex next file, processing (@code{nx})
-Force @code{gtroff} to continue processing of the file specified as an
-argument.  If no argument is given, immediately jump to the end of file.
+Force @command{gtroff} to continue processing of the file specified as
+an argument.  If no argument is given, immediately jump to the end of
+file.
 @endDefreq
 
 @Defreq {rd, [@Var{prompt} [@Var{arg1} @Var{arg2} @dots{}]]}
@@ -16052,9 +16055,9 @@ Dear Mr. Adollar,
 @endExample
 
 @Defreq {pi, pipe}
-Pipe the output of @code{gtroff} to the shell command(s) specified by
-@var{pipe}.  This request must occur before @code{gtroff} has a chance
-to print anything.
+Pipe the output of @command{gtroff} to the shell command(s) specified by
+@var{pipe}.  This request must occur before @command{gtroff} has a
+chance to print anything.
 
 @cindex safer mode
 @cindex mode, safer
@@ -16520,13 +16523,13 @@ command-line option.
 @c =====================================================================
 
 @node Gtroff Internals, Debugging, Miscellaneous, GNU troff Reference
-@section @code{gtroff} Internals
+@section @command{gtroff} Internals
 
 @cindex input token
 @cindex token, input
 @cindex output node
 @cindex node, output
-@code{gtroff} processes input in three steps.  One or more input
+@command{gtroff} processes input in three steps.  One or more input
 characters are converted to an @dfn{input token}.@footnote{Except the
 escape sequences @code{\f}, @code{\F}, @code{\H}, @code{\m}, @code{\M},
 @code{\R}, @code{\s}, and @code{\S}, which are processed immediately if
@@ -16534,10 +16537,10 @@ not in copy mode.}  Then, one or more input tokens 
are converted to
 an @dfn{output node}.  Finally, output nodes are converted to the
 intermediate output language understood by all output devices.
 
-Actually, before step one happens, @code{gtroff} converts certain escape
-sequences into reserved input characters (not accessible by the user);
-such reserved characters are used for other internal processing also --
-this is the very reason why not all characters are valid input.
+Actually, before step one happens, @command{gtroff} converts certain
+escape sequences into reserved input characters (not accessible by the
+user); such reserved characters are used for other internal processing
+also -- this is the very reason why not all characters are valid input.
 @xref{Identifiers}, for more on this topic.
 
 For example, the input string @samp{fi\[:u]} is converted into a
@@ -16548,8 +16551,8 @@ representing the ligature glyph @samp{fi} (provided the 
current font has
 a glyph for this ligature); the same happens with @samp{:u}.  All output
 glyph nodes are `processed', which means that they are invariably
 associated with a given font, font size, advance width, etc.  During the
-formatting process, @code{gtroff} itself adds various nodes to control
-the data flow.
+formatting process, @command{gtroff} itself adds various nodes to
+control the data flow.
 
 Macros, diversions, and strings collect elements in two chained lists: a
 list of input tokens that have been passed unprocessed, and a list of
@@ -16583,10 +16586,10 @@ It contains these elements.
 
 @cindex @code{\v}, internal representation
 @noindent
-Elements 1, 7, and@tie{}8 are inserted by @code{gtroff}; the latter two
-(which are always present) specify the vertical extent of the last line,
-possibly modified by @code{\x}.  The @code{br} request finishes the
-pending output line, inserting a newline input token, which is
+Elements 1, 7, and@tie{}8 are inserted by @command{gtroff}; the latter
+two (which are always present) specify the vertical extent of the last
+line, possibly modified by @code{\x}.  The @code{br} request finishes
+the pending output line, inserting a newline input token, which is
 subsequently converted to a space when the diversion is interpolated.
 Note that the word space node has a fixed width that isn't adjustable
 anymore.  To convert horizontal space nodes back to input tokens, use
@@ -16805,13 +16808,13 @@ planted but subsequently (re)moved, are printed as 
well.
 @Defreq {fl, }
 @cindex flush output (@code{fl})
 @cindex output, flush (@code{fl})
-@cindex interactive use of @code{gtroff}
-@cindex @code{gtroff}, interactive use
-Instruct @code{gtroff} to flush its output immediately.  The intent is
-for interactive use, but this behaviour is currently not implemented in
-@code{gtroff}.  Contrary to Unix @code{troff}, TTY output is sent to a
-device driver also (@code{grotty}), making it non-trivial to communicate
-interactively.
+@cindex interactive use of @command{gtroff}
+@cindex @command{gtroff}, interactive use
+Instruct @command{gtroff} to flush its output immediately.  The intent
+is for interactive use, but this behaviour is currently not implemented
+in @command{gtroff}.  Contrary to Unix @code{troff}, TTY output is sent
+to a device driver also (@code{grotty}), making it non-trivial to
+communicate interactively.
 
 This request causes a line break.
 @endDefreq
@@ -16874,8 +16877,8 @@ For example,
 
 @noindent
 causes a warning if @code{break} warnings are not suppressed and
-@code{gtroff} must add 0.2@dmn{m} or more for each inter-word space in a
-line.  @xref{Warnings}.
+@command{gtroff} must add 0.2@dmn{m} or more for each inter-word space
+in a line.  @xref{Warnings}.
 @endDefreq
 
 @cindex warnings
@@ -17495,7 +17498,7 @@ partially collected line at the end of input; GNU 
@code{troff} will not.
 @cindex file formats
 @cindex formats, file
 
-All files read and written by @code{gtroff} are text files.  The
+All files read and written by @command{gtroff} are text files.  The
 following two sections describe their format.
 
 @menu
@@ -17511,9 +17514,9 @@ following two sections describe their format.
 
 @c BEGIN TODO: Make parallel with groff_out(5).
 @node gtroff Output, Device and Font Description Files, File Formats, File 
Formats
-@section @code{gtroff} Output
-@cindex @code{gtroff}, output
-@cindex output, @code{gtroff}
+@section @command{gtroff} Output
+@cindex @command{gtroff}, output
+@cindex output, @command{gtroff}
 
 This section describes the @code{groff} intermediate output format
 produced by GNU @code{troff}.
@@ -17543,16 +17546,16 @@ and postprocessor for intermediate output can be 
found in the file@*
 The main purpose of the intermediate output concept is to facilitate the
 development of postprocessors by providing a common programming
 interface for all devices.  It has a language of its own that is
-completely different from the @code{gtroff} language.  While the
-@code{gtroff} language is a high-level programming language for text
+completely different from the @command{gtroff} language.  While the
+@command{gtroff} language is a high-level programming language for text
 processing, the intermediate output language is a kind of low-level
 assembler language by specifying all positions on the page for writing
 and drawing.
 
-The intermediate output produced by @code{gtroff} is fairly readable,
+The intermediate output produced by @command{gtroff} is fairly readable,
 while output from @acronym{AT&T} @code{troff} is rather hard to
 understand because of strange habits that are still supported, but not
-used any longer by @code{gtroff}.
+used any longer by @command{gtroff}.
 
 @menu
 * Language Concepts::
@@ -17591,10 +17594,10 @@ formats.
 @subsubsection Separation
 
 @acronym{AT&T} @code{troff} output has strange requirements regarding
-whitespace.  The @code{gtroff} output parser, however, is more tolerant,
-making whitespace maximally optional.  Such characters, i.e., the tab,
-space, and newline, always have a syntactical meaning.  They are never
-printable because spacing within the output is always done by
+whitespace.  The @command{gtroff} output parser, however, is more
+tolerant, making whitespace maximally optional.  Such characters, i.e.,
+the tab, space, and newline, always have a syntactical meaning.  They
+are never printable because spacing within the output is always done by
 positioning commands.
 
 Any sequence of space or tab characters is treated as a single
@@ -17614,8 +17617,8 @@ newline character.
 The normal commands, those for positioning and text, consist of a single
 letter taking a fixed number of arguments.  For historical reasons, the
 parser allows stacking of such commands on the same line, but
-fortunately, in @code{gtroff}'s intermediate output, every command with
-at least one argument is followed by a line break, thus providing
+fortunately, in @command{gtroff}'s intermediate output, every command
+with at least one argument is followed by a line break, thus providing
 excellent readability.
 
 The other commands---those for drawing and device controlling---have a
@@ -17659,7 +17662,7 @@ A correct intermediate output document consists of two 
parts, the
 @dfn{prologue} and the @dfn{body}.
 
 The task of the prologue is to set the general device parameters using
-three exactly specified commands.  @code{gtroff}'s prologue is
+three exactly specified commands.  @command{gtroff}'s prologue is
 guaranteed to consist of the following three lines (in that order):
 
 @Example
@@ -17677,7 +17680,7 @@ The body is the main section for processing the 
document data.
 Syntactically, it is a sequence of any commands different from the ones
 used in the prologue.  Processing is terminated as soon as the first
 @w{@samp{x stop}} command is encountered; the last line of any
-@code{gtroff} intermediate output always contains such a command.
+@command{gtroff} intermediate output always contains such a command.
 
 Semantically, the body is page oriented.  A new page is started by a
 @samp{p} command.  Positioning, writing, and drawing commands are always
@@ -17692,7 +17695,7 @@ done relative to the current location within this page.
 @subsection Command Reference
 
 This section describes all intermediate output commands, both from
-@acronym{AT&T} @code{troff} as well as the @code{gtroff} extensions.
+@acronym{AT&T} @code{troff} as well as the @command{gtroff} extensions.
 
 @menu
 * Comment Command::
@@ -17877,7 +17880,7 @@ command may not be followed by another command on the 
same line (apart
 from a comment), so each @samp{D} command is terminated by a syntactical
 line break.
 
-@code{gtroff} output follows the classical spacing rules (no space
+@command{gtroff} output follows the classical spacing rules (no space
 between command and subcommand, all arguments are preceded by a single
 space character), but the parser allows optional space between the
 command letters and makes the space before the first argument optional.
@@ -17891,7 +17894,7 @@ left.  The arguments called @var{v1}, @var{v2}, 
@dots{}, @var{vn} stand
 for vertical distances where positive means down, negative up.  All
 these distances are offsets relative to the current location.
 
-Each graphics command directly corresponds to a similar @code{gtroff}
+Each graphics command directly corresponds to a similar @command{gtroff}
 @code{\D} escape sequence.  @xref{Drawing Geometric Objects}.
 
 Unknown @samp{D} commands are assumed to be device-specific.  Its
@@ -17922,7 +17925,7 @@ diameter@tie{}@var{d} (integer in basic units @samp{u}) 
with leftmost
 point at the current position; then move the current position to the
 rightmost point of the circle.  An optional second integer argument is
 ignored (this allows the formatter to generate an even number of
-arguments).  This command is a @code{gtroff} extension.
+arguments).  This command is a @command{gtroff} extension.
 
 @item Dc @var{d}@angles{line break}
 Draw circle line with diameter@tie{}@var{d} (integer in basic units
@@ -17934,7 +17937,7 @@ Draw a solid ellipse in the current fill color with a 
horizontal
 diameter of@tie{}@var{h} and a vertical diameter of@tie{}@var{v} (both
 integers in basic units @samp{u}) with the leftmost point at the current
 position; then move to the rightmost point of the ellipse.  This command
-is a @code{gtroff} extension.
+is a @command{gtroff} extension.
 
 @item De @var{h} @var{v}@angles{line break}
 Draw an outlined ellipse with a horizontal diameter of@tie{}@var{h} and
@@ -17948,10 +17951,10 @@ the analogous command for setting the color of text, 
line graphics, and
 the outline of graphic objects is @samp{m}.  The color components are
 specified as integer arguments between 0 and 65535.  The number of color
 components and their meaning vary for the different color schemes.
-These commands are generated by @code{gtroff}'s escape sequences
+These commands are generated by @command{gtroff}'s escape sequences
 @samp{\D'F @dots{}'} and @code{\M} (with no other corresponding
 graphics commands).  No position changing.  This command is a
-@code{gtroff} extension.
+@command{gtroff} extension.
 
 @table @code
 @item DFc @var{cyan} @var{magenta} @var{yellow}@angles{line break}
@@ -18004,7 +18007,7 @@ sets all colors to blue.
 @end table
 
 @noindent
-No position changing.  This command is a @code{gtroff} extension.
+No position changing.  This command is a @command{gtroff} extension.
 
 @item Dl @var{h} @var{v}@angles{line break}
 Draw line from current position to offset (@var{h},@var{v}) (integers in
@@ -18023,7 +18026,7 @@ kept for compatibility.
 As the polygon is closed, the end of drawing is the starting point, so
 the position doesn't change.
 @end ignore
-This command is a @code{gtroff} extension.
+This command is a @command{gtroff} extension.
 
 @item DP @var{h1} @var{v1} @var{h2} @var{v2} @dots{} @var{hn} 
@var{vn}@angles{line break}
 Draw a solid polygon in the current fill color rather than an outlined
@@ -18032,7 +18035,7 @@ polygon, using the same arguments and positioning as 
the corresponding
 @ignore
 No position changing.
 @end ignore
-This command is a @code{gtroff} extension.
+This command is a @command{gtroff} extension.
 
 @item Dt @var{n}@angles{line break}
 Set the current line thickness to@tie{}@var{n} (an integer in basic
@@ -18046,26 +18049,26 @@ Although this doesn't make sense it is kept for 
compatibility.
 @ignore
 No position changing.
 @end ignore
-This command is a @code{gtroff} extension.
+This command is a @command{gtroff} extension.
 @end table
 
 @node Device Control Commands, Obsolete Command, Graphics Commands, Command 
Reference
 @subsubsection Device Control Commands
 
 Each device control command starts with the letter @samp{x}, followed by
-a space character (optional or arbitrary space or tab in @code{gtroff})
-and a subcommand letter or word; each argument (if any) must be preceded
-by a syntactical space.  All @samp{x} commands are terminated by a
-syntactical line break; no device control command can be followed by
-another command on the same line (except a comment).
+a space character (optional or arbitrary space or tab in
+@command{gtroff}) and a subcommand letter or word; each argument (if
+any) must be preceded by a syntactical space.  All @samp{x} commands are
+terminated by a syntactical line break; no device control command can be
+followed by another command on the same line (except a comment).
 
 The subcommand is basically a single letter, but to increase
 readability, it can be written as a word, i.e., an arbitrary sequence of
 characters terminated by the next tab, space, or newline character.  All
 characters of the subcommand word but the first are simply ignored.  For
-example, @code{gtroff} outputs the initialization command @w{@samp{x i}}
-as @w{@samp{x init}} and the resolution command @w{@samp{x r}} as
-@w{@samp{x res}}.
+example, @command{gtroff} outputs the initialization command
+@w{@samp{x i}} as @w{@samp{x init}} and the resolution command
+@w{@samp{x r}} as @w{@samp{x res}}.
 
 In the following, the syntax element @angles{line break} means a
 syntactical line break (@pxref{Separation}).
@@ -18076,8 +18079,9 @@ The @samp{F} stands for @var{Filename}.
 
 Use @var{name} as the intended name for the current file in error
 reports.  This is useful for remembering the original file name when
-@code{gtroff} uses an internal piping mechanism.  The input file is not
-changed by this command.  This command is a @code{gtroff} extension.
+@command{gtroff} uses an internal piping mechanism.  The input file is
+not changed by this command.  This command is a @command{gtroff}
+extension.
 
 @item xf @var{n} @var{s}@angles{line break}
 The @samp{f} stands for @var{font}.
@@ -18148,7 +18152,7 @@ The @samp{u} stands for @var{underline}.
 Configure underlining of spaces.  If @var{n} is@tie{}1, start
 underlining of spaces; if @var{n} is@tie{}0, stop underlining of spaces.
 This is needed for the @code{cu} request in @code{nroff} mode and is
-ignored otherwise.  This command is a @code{gtroff} extension.
+ignored otherwise.  This command is a @command{gtroff} extension.
 
 @item xX @var{anything}@angles{line break}
 The @samp{x} stands for @var{X-escape}.
@@ -18159,8 +18163,8 @@ interpreted as a continuation line in the following 
sense.  The @samp{+}
 is ignored, but a newline character is sent instead to the device, the
 rest of the line is sent uninterpreted.  The same applies to all
 following lines until the first character of a line is not a @samp{+}
-character.  This command is generated by the @code{gtroff} escape
-sequence @code{\X}.  The line-continuing feature is a @code{gtroff}
+character.  This command is generated by the @command{gtroff} escape
+sequence @code{\X}.  The line-continuing feature is a @command{gtroff}
 extension.
 @end table
 
@@ -18187,9 +18191,10 @@ unreadable.
 
 For modern high-resolution devices, this command does not make sense
 because the width of the glyphs can become much larger than two decimal
-digits.  In @code{gtroff}, this is only used for the devices @code{X75},
-@code{X75-12}, @code{X100}, and @code{X100-12}.  For other devices, the
-commands @samp{t} and @samp{u} provide a better functionality.
+digits.  In @command{gtroff}, this is only used for the devices
+@code{X75}, @code{X75-12}, @code{X100}, and @code{X100-12}.  For other
+devices, the commands @samp{t} and @samp{u} provide a better
+functionality.
 
 @c ---------------------------------------------------------------------
 
@@ -18198,13 +18203,13 @@ commands @samp{t} and @samp{u} provide a better 
functionality.
 
 This section presents the intermediate output generated from the same
 input for three different devices.  The input is the sentence @samp{hell
-world} fed into @code{gtroff} on the command line.
+world} fed into @command{gtroff} on the command line.
 
 @table @asis
 @item High-resolution device @code{ps}
 
-This is the standard output of @code{gtroff} if no @option{-T} option is
-given.
+This is the standard output of @command{gtroff} if no @option{-T} option
+is given.
 
 @example
 @group
@@ -18354,7 +18359,7 @@ the postprocessor programs.
 
 @item
 The argument of the commands @samp{s} and @w{@samp{x H}} has the
-implicit unit scaled point @samp{z} in @code{gtroff}, while
+implicit unit scaled point @samp{z} in @command{gtroff}, while
 @acronym{AT&T} @code{troff} has point (@samp{p}).  This isn't an
 incompatibility but a compatible extension, for both units coincide for
 all devices without a @code{sizescale} parameter in the @file{DESC}
@@ -18366,8 +18371,8 @@ resolution.  So conflicts are very unlikely.
 
 @item
 The position changing after the commands @samp{Dp}, @samp{DP}, and
-@samp{Dt} is illogical, but as old versions of @code{gtroff} used this
-feature it is kept for compatibility reasons.
+@samp{Dt} is illogical, but as old versions of @command{gtroff} used
+this feature, it is kept for compatibility reasons.
 
 @ignore
 Temporarily, there existed some confusion on the positioning after the