Ubuntu Manpage: groff_man - compose manual pages with GNU roff

Name

       groff_man - compose manual pages with GNU roff

Synopsis

       groff -man [option ...] [file ...]
       groff -m man [option ...] [file ...]

Description

The GNU implementation of the man macro package is part of the groff document formatting system. It is
used to produce manual pages (“man pages”) like the one you are reading.

This document presents the macros thematically; for those needing only a quick reference, the following
table lists them alphabetically, with cross references to appropriate subsections below.

Man page authors and maintainers who are not already experienced groff users should consult
groff_man_style(7), an expanded version of this document, for additional explanations and advice. It
covers only those concepts required for man page document maintenance, and not the full breadth of the
groff typesetting system.

Macro Meaning Subsection
───────────────────────────────────────────────────────────────
.B Bold Font style macros
.BI Bold, italic alternating Font style macros
.BR Bold, roman alternating Font style macros
.EE Example end Document structure macros
.EX Example begin Document structure macros
.I Italic Font style macros
.IB Italic, bold alternating Font style macros
.IP Indented paragraph Paragraphing macros
.IR Italic, roman alternating Font style macros
.LP Begin paragraph Paragraphing macros
.ME Mail-to end Hyperlink macros
.MR Man page cross reference Hyperlink macros
.MT Mail-to start Hyperlink macros
.P Begin paragraph Paragraphing macros
.PP Begin paragraph Paragraphing macros
.RB Roman, bold alternating Font style macros
.RE Relative inset end Document structure macros
.RI Roman, italic alternating Font style macros
.RS Relative inset start Document structure macros
.SB Small bold Font style macros
.SH Section heading Document structure macros
.SM Small Font style macros
.SS Subsection heading Document structure macros
.SY Synopsis start Command synopsis macros
.TH Title heading Document structure macros
.TP Tagged paragraph Paragraphing macros
.TQ Supplemental paragraph tag Paragraphing macros
.UE URI end Hyperlink macros
.UR URI start Hyperlink macros
.YS Synopsis end Command synopsis macros

We discuss other macros (.AT, .DT, .HP, .OP, .PD, and .UC) in subsection “Deprecated features” below.

Throughout Unix documentation, a manual entry is referred to simply as a “man page”, regardless of its
length, without gendered implication, and irrespective of the macro package selected for its composition.

Macro reference preliminaries
A tagged paragraph describes each macro. We present coupled pairs together, as with .EX and .EE.

An empty macro argument can be specified with a pair of double-quotes (""), but the man package is
designed such that this should seldom be necessary. Most macro arguments will be formatted as text in
the output; exceptions are noted.

Document structure macros
Document structure macros organize a man page's content. All of them break the output line. .TH (title
heading) identifies the document as a man page and configures the page headers and footers. Section
headings (.SH), one of which is mandatory and many of which are conventionally expected, facilitate
location of material by the reader and aid the man page writer to discuss all essential aspects of the
topic. Subsection headings (.SS) are optional and permit sections that grow long to develop in a
controlled way. Many technical discussions benefit from examples; lengthy ones, especially those
reflecting multiple lines of input to or output from the system, are usefully bracketed by .EX and .EE.
When none of the foregoing meets a structural demand, use .RS/.RE to inset a region within a
(sub)section.

.TH topic section [footer-middle] [footer-inside] [header-middle]
Determine the contents of the page header and footer. The subject of the man page is topic and
the section of the manual to which it belongs is section. See man(1) or intro(1) for the manual
sectioning applicable to your system. topic and section are positioned together at the left and
right in the header (with section in parentheses immediately appended to topic). footer-middle is
centered in the footer. The arrangement of the rest of the footer depends on whether double-sided
layout is enabled with the option -rD1. When disabled (the default), footer-inside is positioned
at the bottom left. Otherwise, footer-inside appears at the bottom left on recto (odd-numbered)
pages, and at the bottom right on verso (even-numbered) pages. The outside footer is the page
number, except in the continuous-rendering mode enabled by the option -rcR=1, in which case it is
the topic and section, as in the header. header-middle is centered in the header. If section is
an integer between 1 and 9 (inclusive), there is no need to specify header-middle; an.tmac will
supply text for it. The macro package may also abbreviate topic and footer-inside with ellipses
if they would overrun the space available in the header and footer, respectively. For HTML
output, headers and footers are suppressed.

Additionally, this macro breaks the page, resetting the number to 1 (unless the -rC1 option is
given). This feature is intended only for formatting multiple man documents in sequence.

A valid man document calls .TH once, early in the file, prior to any other macro calls.

.SH [heading-text]
Set heading-text as a section heading. If no argument is given, a one-line input trap is planted;
text on the next line becomes heading-text. The left margin is reset to zero to set the heading
text in bold (or the font specified by the string HF), and, on typesetting devices, slightly
larger than the base type size. If the heading font \*[HF] is bold, use of an italic style in
heading-text is mapped to the bold-italic style if available in the font family. The inset level
is reset to 1, setting the left margin to the value of the IN register. Text after heading-text
is set as an ordinary paragraph (.P).

The content of heading-text and ordering of sections follows a set of common practices, as has
much of the layout of material within sections. For example, a section called “Name” or “NAME”
must exist, must be the first section after the .TH call, and must contain only text of the form
topic[, another-topic]... \- summary-description
for a man page to be properly indexed. See groff_man_style(7) for suggestions and man(7) for the
conventions prevailing on your system.

.SS [subheading-text]
Set subheading-text as a subsection heading indented between a section heading and an ordinary
paragraph (.P). If no argument is given, a one-line input trap is planted; text on the next line
becomes subheading-text. The left margin is reset to the value of the SN register to set the
heading text in bold (or the font specified by the string HF). If the heading font \*[HF] is
bold, use of an italic style in subheading-text is mapped to the bold-italic style if available in
the font family. The inset level is reset to 1, setting the left margin to the value of the IN
register. Text after subheading-text is set as an ordinary paragraph (.P).

.EX
.EE Begin and end example. After .EX, filling is disabled and a constant-width (monospaced) font is
selected. Calling .EE enables filling and restores the previous font.

These macros are extensions introduced in Ninth Edition Research Unix. Systems running that
troff, or those from Documenter's Workbench, Heirloom Doctools, or Plan 9 troff support them. To
be certain your page will be portable to systems that do not, copy their definitions from the
an-ext.tmac file of a groff installation.

.RS [inset-amount]
Start a new relative inset level. The position of the left margin is saved, then moved right by
inset-amount, if specified, and by the amount of the IN register otherwise. Calls to .RS can be
nested; each increments by 1 the inset level used by .RE. The level prior to any .RS calls is 1.

.RE [level]
End a relative inset. The left margin corresponding to inset level level is restored. If no
argument is given, the inset level is reduced by 1.

Paragraphing macros
An ordinary paragraph (.P) is set without a first-line indentation at the current left margin. In man
pages and other technical literature, definition lists are frequently encountered; these can be set as
“tagged paragraphs”, which have one (.TP) or more (.TQ) leading tags followed by a paragraph that has an
additional indentation. The indented paragraph (.IP) macro is useful to continue the indented content of
a narrative started with .TP, or to present an itemized or ordered list. All of these macros break the
output line. If another paragraph macro has occurred since the previous .SH or .SS, they (except for
.TQ) follow the break with a default amount of vertical space, which can be changed by the deprecated .PD
macro; see subsection “Horizontal and vertical spacing” below. They also reset the type size and font
style to defaults (.TQ again excepted); see subsection “Font style macros” below.

.P
.LP
.PP Begin a new paragraph; these macros are synonymous. The indentation is reset to the default
value; the left margin, as affected by .RS and .RE, is not.

.TP [indentation]
Set a paragraph with a leading tag, and the remainder of the paragraph indented. A one-line input
trap is planted; text on the next line, which can be formatted with a macro, becomes the tag,
which is placed at the current left margin. The tag can be extended with the \c escape sequence.
Subsequent text is indented by indentation, if specified, and by the amount of the IN register
otherwise. If the tag is not as wide as the indentation, the paragraph starts on the same line as
the tag, at the applicable indentation, and continues on the following lines. Otherwise, the
descriptive part of the paragraph begins on the line following the tag.

.TQ Set an additional tag for a paragraph tagged with .TP. An input trap is planted as with .TP.

This macro is a GNU extension not defined on systems running AT&T, Plan 9, or Solaris troff; see
an-ext.tmac in section “Files” below.

.IP [tag] [indentation]
Set an indented paragraph with an optional tag. The tag and indentation arguments, if present,
are handled as with .TP, with the exception that the tag argument to .IP cannot include a macro
call.

Command synopsis macros
.SY and .YS aid you to construct a command synopsis that has the classical Unix appearance. They break
the output line.

These macros are GNU extensions not defined on systems running AT&T, Plan 9, or Solaris troff; see
an-ext.tmac in section “Files” below.

.SY command
Begin synopsis. A new paragraph begins at the left margin unless .SY has already been called
without a corresponding .YS, in which case only a break is performed. Adjustment and automatic
hyphenation are disabled. command is set in bold. If a break is required, lines after the first
are indented by the width of command plus a space.

.YS End synopsis. Indentation, adjustment, and hyphenation are restored to their previous states.

Hyperlink macros
Man page cross references are best presented with .MR. Text may be hyperlinked to email addresses with
.MT/.ME or other URIs with .UR/.UE. Hyperlinked text is supported on HTML and terminal output devices;
terminals and pager programs must support ECMA-48 OSC 8 escape sequences (see grotty(1)). When device
support is unavailable or disabled with the U register (see section “Options” below), .MT and .UR URIs
are rendered between angle brackets after the linked text.

.MT, .ME, .UR, and .UE are GNU extensions not defined on systems running AT&T, Plan 9, or Solaris troff;
see an-ext.tmac in section “Files” below. Plan 9 from User Space's troff implements .MR.

The arguments to .MR, .MT, and .UR should be prepared for typesetting since they can appear in the
output. Use special character escape sequences to encode Unicode basic Latin characters where necessary,
particularly the hyphen-minus. The formatter removes \: escape sequences from hyperlinks when supplying
device control commands to output drivers.

.MR topic manual-section [trailing-text]
(since groff 1.23) Set a man page cross reference as “topic(manual-section)”. If trailing-text
(typically punctuation) is specified, it follows the closing parenthesis without intervening
space. Hyphenation is disabled while the cross reference is set. topic is set in the font
specified by the MF string. The cross reference hyperlinks to a URI of the form
“man:topic(manual-section)”.

.MT address
.ME [trailing-text]
Identify address as an RFC 6068 addr-spec for a “mailto:” URI with the text between the two macro
calls as the link text. An argument to .ME is placed after the link text without intervening
space. address may not be visible in the rendered document if hyperlinks are enabled and
supported by the output driver. If they are not, address is set in angle brackets after the link
text and before trailing-text. If hyperlinking is enabled but there is no link text, address is
formatted and hyperlinked without angle brackets.

.UR uri
.UE [trailing-text]
Identify uri as an RFC 3986 URI hyperlink with the text between the two macro calls as the link
text. An argument to .UE is placed after the link text without intervening space. uri may not be
visible in the rendered document if hyperlinks are enabled and supported by the output driver. If
they are not, uri is set in angle brackets after the link text and before trailing-text. If
hyperlinking is enabled but there is no link text, uri is formatted and hyperlinked without angle
brackets.

The hyperlinking of .TP paragraph tags with .UR/.UE and .MT/.ME is not yet supported; if attempted, the
hyperlink will be typeset at the beginning of the indented paragraph even on hyperlink-supporting
devices.

Font style macros
The man macro package is limited in its font styling options, offering only bold (.B), italic (.I), and
roman. Italic text is usually set underscored instead on terminal devices. The .SM and .SB macros set
text in roman or bold, respectively, at a smaller type size; these differ visually from regular-sized
roman or bold text only on typesetting devices. It is often necessary to set text in different styles
without intervening space. The macros .BI, .BR, .IB, .IR, .RB, and .RI, where “B”, “I”, and “R” indicate
bold, italic, and roman, respectively, set their odd- and even-numbered arguments in alternating styles,
with no space separating them.

The default type size and family for typesetting devices is 10-point Times, except on the X75-12 and
X100-12 devices where the type size is 12 points. The default style is roman.

.B [text]
Set text in bold. If no argument is given, a one-line input trap is planted; text on the next
line, which can be further formatted with a macro, is set in bold.

.I [text]
Set text in an italic or oblique face. If no argument is given, a one-line input trap is planted;
text on the next line, which can be further formatted with a macro, is set in an italic or oblique
face.

.SM [text]
Set text one point smaller than the default type size on typesetting devices. If no argument is
given, a one-line input trap is planted; text on the next line, which can be further formatted
with a macro, is set smaller.

.SB [text]
Set text in bold and (on typesetting devices) one point smaller than the default type size. If no
argument is given, a one-line input trap is planted; text on the next line, which can be further
formatted with a macro, is set smaller and in bold. This macro is an extension introduced in
SunOS 4.0.

Unlike the above font style macros, the font style alternation macros below set no input traps; they must
be given arguments to have effect. Italic corrections are applied as appropriate.

.BI bold-text italic-text ...
Set each argument in bold and italics, alternately.

.BR bold-text roman-text ...
Set each argument in bold and roman, alternately.

.IB italic-text bold-text ...
Set each argument in italics and bold, alternately.

.IR italic-text roman-text ...
Set each argument in italics and roman, alternately.

.RB roman-text bold-text ...
Set each argument in roman and bold, alternately.

.RI roman-text italic-text ...
Set each argument in roman and italics, alternately.

Horizontal and vertical spacing
The indentation argument accepted by .IP, .TP, and the deprecated .HP is a number plus an optional
scaling unit, as is .RS's inset-amount. If no scaling unit is given, the man package assumes “n”. An
indentation specified in a call to .IP, .TP, or the deprecated .HP persists until (1) another of these
macros is called with an indentation argument, or (2) .SH, .SS, or .P or its synonyms is called; these
clear the indentation entirely.

The left margin used by ordinary paragraphs set with .P (and its synonyms) not within an .RS/.RE relative
inset is 7.2n for typesetting devices and 7n for terminal devices (but see the -rIN option). Headers,
footers (both set with .TH), and section headings (.SH) are set at the page offset (see groff(7)) and
subsection headings (.SS) indented from it by 3n (but see the -rSN option).

Several macros insert vertical space: .SH, .SS, .TP, .P (and its synonyms), .IP, and the deprecated .HP.
The default inter-section and inter-paragraph spacing is is 1v for terminal devices and 0.4v for
typesetting devices. (The deprecated macro .PD can change this vertical spacing, but its use is
discouraged.) Between .EX and .EE calls, the inter-paragraph spacing is 1v regardless of output device.

Registers
Registers are described in section “Options” below. They can be set not only on the command line but in
the site man.local file as well; see section “Files” below.

Strings
The following strings are defined for use in man pages. None of these is necessary in a contemporary man
page; see groff_man_style(7). Others are supported for configuration of rendering parameters; see
section “Options” below.

\*R interpolates a special character escape sequence for the “registered sign” glyph, \(rg, if
available, and “(Reg.)” otherwise.

\*S interpolates an escape sequence setting the type size to the document default.

\*(lq
\*(rq interpolate special character escape sequences for left and right double-quotation marks, \(lq and
\(rq, respectively.

\*(Tm interpolates a special character escape sequence for the “trade mark sign” glyph, \(tm, if
available, and “(TM)” otherwise.

Hooks
Two macros, both GNU extensions, are called internally by the groff man package to format page headers
and footers and can be redefined by the administrator in a site's man.local file (see section “Files”
below). The presentation of .TH above describes the default headers and footers. Because these macros
are hooks for groff man internals, man pages have no reason to call them. Such hook definitions will
likely consist of “.sp” and “.tl” requests. They must also increase the page length with “.pl” requests
in continuous rendering mode; .PT furthermore has the responsibility of emitting a PDF bookmark after
writing the first page header in a document. Consult the existing implementations in an.tmac when
drafting replacements.

.BT Set the page footer text (“bottom trap”).

.PT Set the page header text (“page trap”).

To remove a page header or footer entirely, define the appropriate macro as empty rather than deleting
it.

Deprecated features
Use of the following in man pages for public distribution is discouraged.

.AT [system [release]]
Alter the footer for use with legacy AT&T man pages, overriding any definition of the footer-
inside argument to .TH. This macro exists only to render man pages from historical systems.

system can be any of the following.

3 7th edition (default)

4 System III

5 System V

The optional release argument specifies the release number, as in “System V Release 3”.

.DT Reset tab stops to the default (every 0.5i).

Use of this presentation-oriented macro is deprecated. It translates poorly to HTML, under which
exact space control and tabulation are not readily available. Thus, information or distinctions
that you use tab stops to express are likely to be lost. If you feel tempted to change the tab
stops such that calling this macro later is desirable to restore them, you should probably be
composing a table using tbl(1) instead.

.HP [indentation]
Set up a paragraph with a hanging left indentation. The indentation argument, if present, is
handled as with .TP.

Use of this presentation-oriented macro is deprecated. A hanging indentation cannot be expressed
naturally under HTML, and non-roff-based man page interpreters may treat .HP as an ordinary
paragraph. Thus, information or distinctions you mean to express with indentation may be lost.

.OP option-name [option-argument]
Indicate an optional command parameter called option-name, which is set in bold. If the option
takes an argument, specify option-argument using a noun, abbreviation, or hyphenated noun phrase.
If present, option-argument is preceded by a space and set in italics. Square brackets in roman
surround both arguments.

Use of this quasi-semantic macro, an extension originating in Documenter's Workbench troff, is
deprecated. It cannot easily be used to annotate options that take optional arguments or options
whose arguments have internal structure (such as a mixture of literal and variable components).
One could work around these limitations with font selection escape sequences, but it is preferable
to use font style alternation macros, which afford greater flexibility.

.PD [vertical-space]
Define the vertical space between paragraphs or (sub)sections. The optional argument vertical-
space specifies the amount; the default scaling unit is “v”. Without an argument, the spacing is
reset to its default value; see subsection “Horizontal and vertical spacing” above.

Use of this presentation-oriented macro is deprecated. It translates poorly to HTML, under which
exact control of inter-paragraph spacing is not readily available. Thus, information or
distinctions that you use .PD to express are likely to be lost.

.UC [version]
Alter the footer for use with legacy BSD man pages, overriding any definition of the footer-inside
argument to .TH. This macro exists only to render man pages from historical systems.

version can be any of the following.

3 3rd Berkeley Distribution (default)

4 4th Berkeley Distribution

5 4.2 Berkeley Distribution

6 4.3 Berkeley Distribution

7 4.4 Berkeley Distribution

History
M. Douglas McIlroy ⟨m.douglas.mcilroy@dartmouth.edu⟩ designed, implemented, and documented the AT&T man
macros for Unix Version 7 (1979) and employed them to edit the first volume of its Programmer's Manual, a
compilation of all man pages supplied by the system. That man supported the macros listed in this page
not described as extensions, except .P and the deprecated .AT and .UC. The only strings defined were R
and S; no registers were documented.

.UC appeared in 3BSD (1980). Unix System III (1980) introduced .P and exposed the registers IN and LL,
which had been internal to Seventh Edition Unix man. PWB/UNIX 2.0 (1980) added the Tm string. 4BSD
(1980) added lq and rq strings. SunOS 2.0 (1985) recognized C, D, P, and X registers. 4.3BSD (1986)
added .AT and .P. Ninth Edition Research Unix (1986) introduced .EX and .EE. SunOS 4.0 (1988) added
.SB.

The foregoing features were what James Clark implemented in early versions of groff. Later, groff 1.20
(2009) originated .SY/.YS, .TQ, .MT/.ME, and .UR/.UE. Plan 9 from User Space's troff introduced .MR in
2020.

Options

The following groff options set registers (with -r) and strings (with -d) recognized and used by the man
macro package. To ensure rendering consistent with output device capabilities and reader preferences,
man pages should never manipulate them.

-dAD=adjustment-mode
Set line adjustment to adjustment-mode, which is typically “b” for adjustment to both margins (the
default), or “l” for left alignment (ragged right margin). Any valid argument to groff's “.ad”
request may be used. See groff(7) for less-common choices.

-rcR=1 Enable continuous rendering. Output is not paginated; instead, one (potentially very long) page
is produced. This is the default for terminal and HTML devices. Use -rcR=0 to disable it on
terminal devices; on HTML devices, it cannot be disabled.

-rC1 Number output pages consecutively, in strictly increasing sequence, rather than resetting the page
number to 1 (or the value of register P) with each new man document.

-rCS=1 Set section headings (the argument(s) to .SH) in full capitals. This transformation is off by
default because it discards case distinction information.

-rCT=1 Set the man page topic (the first argument to .TH) in full capitals in headers and footers. This
transformation is off by default because it discards case distinction information.

-rD1 Enable double-sided layout, formatting footers for even and odd pages differently; see the
description of .TH in subsection “Document structure macros” above.

-rFT=footer-distance
Set distance of the footer relative to the bottom of the page to footer-distance; this amount is
always negative. At one half-inch above this location, the page text is broken before writing the
footer. Ignored if continuous rendering is enabled. The default is -0.5i.

-dHF=heading-font
Set the font used for section and subsection headings; the default is “B” (bold style of the
default family). Any valid argument to groff's “.ft” request may be used. See groff(7).

-rHY=0 Disable automatic hyphenation. Normally, it is enabled (1). The hyphenation mode is determined
by the groff locale; see section “Localization“ of groff(7).

-rIN=standard-indentation
Set the amount of indentation used for ordinary paragraphs (.P and its synonyms) and the default
indentation amount used by .IP, .RS, .TP, and the deprecated .HP. See subsection “Horizontal and
vertical spacing” above for the default. For terminal devices, standard-indentation should always
be an integer multiple of unit “n” to get consistent indentation.

-rLL=line-length
Set line length; the default is 78n for terminal devices and 6.5i for typesetting devices.

-rLT=title-length
Set the line length for titles. By default, it is set to the line length (see -rLL above).

-dMF=man-page-topic-font
Set the font used for man page topics named in .TH and .MR calls; the default is “I” (italic style
of the default family). Any valid argument to groff's “.ft” request may be used. If the MF
string ends in “I”, it is assumed to be an oblique typeface, and italic corrections are applied
before and after man page topics.

-rPn Start enumeration of pages at n. The default is 1.

-rStype-size
Use type-size for the document's body text; acceptable values are 10, 11, or 12 points. See
subsection “Font style macros” above for the default.

-rSN=subsection-indentation
Set indentation of subsection headings to subsection-indentation. See subsection “Horizontal and
vertical spacing” above for the default.

-rU1 Enable generation of URI hyperlinks in the grohtml and grotty output drivers. grohtml enables
them by default; grotty does not, pending more widespread pager support for OSC 8 escape
sequences. Use -rU0 to disable hyperlinks; this will make the arguments to MT and UR calls
visible in the document text produced by link-capable drivers.

-rXp Number successors of page p as pa, pb, pc, and so forth. The register tracking the suffixed page
letter uses format “a” (see the “.af” request in groff(7)).

Files

       /usr/share/groff/1.23.0/tmac/an.tmac
              Most man macros are defined in this file.  It also loads extensions from an-ext.tmac (see below).

       /usr/share/groff/1.23.0/tmac/andoc.tmac
              This brief groff program detects whether the man or mdoc macro package is being used by a document
              and  loads  the correct macro definitions, taking advantage of the fact that pages using them must
              call .TH or .Dd, respectively, before any other  macros.   A  man  program  or  user  typing,  for
              example,  “groff  -mandoc page.1”, need not know which package the file page.1 uses.  Multiple man
              pages, in either format, can be handled; andoc reloads each macro package as necessary.

       /usr/share/groff/1.23.0/tmac/an-ext.tmac
              Except for .SB, definitions of macros described above as extensions are contained in this file; in
              some  cases, they are simpler versions of definitions appearing in an.tmac, and are ignored if the
              formatter is GNU troff.  They are written to  be  compatible  with  AT&T  troff  and  permissively
              licensed—not  copylefted.   To reduce the risk of name space collisions, string and register names
              begin only with “m”.  We encourage man page authors who are concerned about portability to  legacy
              Unix  systems to copy these definitions into their pages, and maintainers of troff implementations
              or work-alike systems that format man pages to re-use them.

              The definitions for these macros are read after a page calls .TH, so they will replace any  macros
              of the same names preceding it in your file.  If you use your own implementations of these macros,
              they must be defined after .TH is called to have any effect.  Furthermore, it is  wise  to  define
              such  page-local  macros  (if  at all) after the “Name” section to accommodate timid makewhatis or
              mandb implementations that may give up their scan for indexing material early.

       /usr/share/groff/1.23.0/tmac/man.tmac
              This is a wrapper that loads an.tmac.

       /usr/share/groff/1.23.0/tmac/mandoc.tmac
              This is a wrapper that loads andoc.tmac.

       /usr/share/groff/site-tmac/man.local
              Put site-local changes and customizations into this file.

Authors