Aph Print an appendix page for every new appendix if this
register is non-zero. No output occurs if Aph is zero,
but there is always an appendix entry in the 'List of
contents'.
Cl Contents level (in the range 0 to 14). The contents is
saved if a heading level is lower than or equal to the
value of Cl. Default is 2.
Cp Eject page between list of table, list of figure, etc., if
the value of Cp is zero. Default is 0.
D Debug flag. Values greater than zero produce debug
information of increasing verbosity. A value of 1 gives
information about the progress of formatting. Default
is 0.
De If set to 1, eject after floating display is output.
Default is 0.
Dsp If defined, it controls the space output before and after
static displays. Otherwise the value of Lsp is used.
Df Control floating keep output. This is a number in the
range 0 to 5, with a default value of 5. See .DF.
Ds If set to 1, use the amount of space stored in register
Lsp before and after display. Default is 1.
Ej If set to 1, eject page before each first-level heading.
Default is 0.
Eq Equation labels are left-aligned if set to 0 and right-
aligned if set to 1. Default is 0.
Fs Footnote spacing. Default is 1.
H1 – H7
Heading counters
H1dot Append a dot after the level-one heading number if value
is greater than zero. Default is 1.
H1h A copy of register H1, but it is incremented just before
the page break. Useful in user-defined header macros.
Hb Heading break level. A number in the range 0 to 14, with
a default value of 2. See .H.
Hc Heading centering level. A number in the range 0 to 14,
with a default value of 0. See .H.
Hi Heading temporary indent. A number in the range 0 to 2,
with a default value of 1.
0 no indentation, left margin
1 indent to the right, similar to '.P 1'
2 indent to line up with text part of preceding
heading
Hps Heading pre-space level. If the heading level is less
than or equal to Hps, two lines precede the section
heading instead of one. Default is first level only. The
real amount of lines is controlled by the registers Hps1
and Hps2.
Hps1 Number of lines preceding .H if the heading level is
greater than Hps. Value is in units, default is 0.5.
Hps2 Number of lines preceding .H if the heading level is less
than or equal to Hps. Value is in units, default is 1.
Hs Heading space level. A number in the range 0 to 14, with
a default value of 2. See .H.
Hss Number of lines following .H if the heading level is less
than or equal to Hs. Value is in units, default is 1.
Ht Heading numbering type.
0 multiple levels (1.1.1, 1.1.2, etc.)
1 single level
Default is 0.
Hu Unnumbered heading level. Default is 2.
Hy Hyphenation status of text body.
0 no hyphenation
1 hyphenation on, set to value 6
Default is 0.
Iso Define this register (to any value) on the command line to
use ISO 8601 date format (e.g., '-rIso=1'). See macro
ISODATE above.
L Page length, only for command-line settings.
Letwam Maximum lines in return-address, used in .WA/.WE. Default
is 14.
Lf, Lt, Lx, Le
Enable (1) or disable (0) the printing of List of figures,
List of tables, List of exhibits and List of equations,
respectively. Default values are Lf=1, Lt=1, Lx=1, and
Le=0.
Li List indentation, used by .AL. Default is 6.
Limsp A flag controlling the insertion of space between prefix
and mark in automatic lists (.AL).
0 no space
1 emit space
Ls List space threshold. If current list level is greater
than Ls no spacing occurs around lists. Default is 99.
Lsp The vertical space used by an empty line. The default is
0.5v in troff mode and 1v in nroff mode.
N Page numbering style.
0 normal header for all pages.
1 header replaces footer on first page, header is
empty.
2 page header is removed on the first page.
3 'section-page' numbering style enabled.
4 page header is removed on the first page.
5 'section-page' and 'section-figure' numbering
style enabled.
Default is 0. See also the registers Sectf and Sectp.
Np A flag to control whether paragraphs are numbered.
0 not numbered
1 numbered in first-level headings.
Default is 0.
O Page offset, only for command-line settings.
Of Format of figure, table, exhibit, and equation titles.
0 ". "
1 " - "
Default is 0.
P Current page number, normally the same as '%' unless
'section-page' numbering style is enabled.
Pi Paragraph indentation. Default is 5.
Pgps A flag to control whether header and footer point size
should follow the current settings or just change when the
header and footer are defined.
0 Point size only changes to the current setting
when .PH, .PF, .OH, .EH, .OF, or .OE is
executed.
1 Point size changes after every .S. This is the
default.
Ps Paragraph spacing. Default is 1.
Pt Paragraph type.
0 left-justified
1 indented paragraphs
2 indented paragraphs except after .H, .DE, or
.LE.
Default is 0.
Rpe Set default value for second argument of .RP. Default
is 0.
Sectf A flag controlling 'section-figures' numbering style. A
non-zero value enables this. See also register N.
Sectp A flag controlling 'section-page' numbering style. A non-
zero value enables this. See also register N.
Si Display indentation. Default is 5.
Verbin Indentation for .VERBON. Default is 5n.
W Line length, only for command-line settings.
.mgm Always 1.
