The manual Sections are traditionally defined as follows:
New sentences should be started on new lines. This makes it easier to see the effect of patches, which often operate at the level of individual sentences.
.TH title section date source manual
For those few man-pages pages in Sections 1 and 8, probably you just want to write GNU.
For system calls, just write Linux. (An earlier practice was to write the version number of the kernel from which the manual page was being written/checked. However, this was never done consistently, and so was probably worse than including no version number. Henceforth, avoid including a version number.)
For library calls that are part of glibc or one of the other common GNU libraries, just use GNU C Library, GNU, or an empty string.
For Section 4 pages, use Linux.
In cases of doubt, just write Linux, or GNU.
NAME SYNOPSIS CONFIGURATION [Normally only in Section 4] DESCRIPTION OPTIONS [Normally only in Sections 1, 8] EXIT STATUS [Normally only in Sections 1, 8] RETURN VALUE [Normally only in Sections 2, 3] ERRORS [Typically only in Sections 2, 3] ENVIRONMENT FILES VERSIONS [Normally only in Sections 2, 3] ATTRIBUTES [Normally only in Sections 2, 3] CONFORMING TO NOTES BUGS EXAMPLE SEE ALSOWhere a traditional heading would apply, please use it; this kind of consistency can make the information easier to understand. If you must, you can create your own headings if they make things easier to understand (this can be especially useful for pages in Sections 4 and 5). However, before doing this, consider whether you could use the traditional headings, with some subsections (.SS) within those sections.
The following list elaborates on the contents of each of the above sections.
See man(7) for important details of the line(s) that should follow the .SH NAME command. All words in this line (including the word immediately following the "\-") should be in lowercase, except where English or technical terminological convention dictates otherwise.
For commands, this shows the syntax of the command and its arguments (including options); boldface is used for as-is text and italics are used to indicate replaceable arguments. Brackets ([]) surround optional arguments, vertical bars (|) separate choices, and ellipses (...) can be repeated. For functions, it shows any required data declarations or #include directives, followed by the function declaration.
Where a feature test macro must be defined in order to obtain the declaration of a function (or a variable) from a header file, then the SYNOPSIS should indicate this, as described in feature_test_macros(7).
This section normally appears only in Section 4 pages.
Discuss how it interacts with files and standard input, and what it produces on standard output or standard error. Omit internals and implementation details unless they're critical for understanding the interface. Describe the usual case; for information on command-line options of a program use the OPTIONS section.
When describing new behavior or new flags for a system call or library function, be careful to note the kernel or C library version that introduced the change. The preferred method of noting this information for flags is as part of a .TP list, in the following form (here, for a new system call flag):
This section should appear only for Section 1 and 8 manual pages.
This section should appear only for Section 1 and 8 manual pages.
The error list should be in alphabetical order.
Give the full pathname of these files, and use the installation process to modify the directory part to match user preferences. For many programs, the default installation location is in /usr/local, so your base manual page should use /usr/local as the base.
The following subsections are defined:
As a general rule, every new interface should include a VERSIONS section in its manual page. Unfortunately, many existing manual pages don't include this information (since there was no policy to do so when they were written). Patches to remedy this are welcome, but, from the perspective of programmers writing new code, this information probably matters only in the case of kernel interfaces that have been added in Linux 2.4 or later (i.e., changes since kernel 2.2), and library functions that have been added to glibc since version 2.1 (i.e., changes since glibc 2.0).
The syscalls(2) manual page also provides information about kernel versions in which various system calls first appeared.
The preferred terms to use for the various standards are listed as headings in standards(7).
For a page in Section 2 or 3, this section should note the POSIX.1 version(s) that the call conforms to, and also whether the call is specified in C99. (Don't worry too much about other standards like SUS, SUSv2, and XPG, or the SVr4 and 4.xBSD implementation standards, unless the call was specified in those standards, but isn't in the current version of POSIX.1.)
If the call is not governed by any standards but commonly exists on other systems, note them. If the call is Linux-specific, note this.
If this section consists of just a list of standards (which it commonly does), terminate the list with a period ('.').
For Section 2 and 3 man pages you may find it useful to include subsections (SS) named Linux Notes and Glibc Notes.
In Section 2, use the heading C library/kernel ABI differences to mark off notes that describe the differences (if any) between the C library wrapper function for a system call and the raw system call interface provided by the kernel.
For details on writing example programs, see Example Programs below.
Use of an AUTHORS section is strongly discouraged. Generally, it is better not to clutter every page with a list of (over time potentially numerous) authors; if you write or significantly amend a page, add a copyright notice as a comment in the source file. If you are the author of a device driver and want to include an address for reporting bugs, place this under the BUGS section.
The list should be ordered by section number and then alphabetically by name Do not terminate this with a period.
For functions, the arguments are always specified using italics, even in the SYNOPSIS section, where the rest of the function is specified in bold:
int myfunction(int argc, char **argv);
Variable names should, like argument names, be specified in italics.
Filenames (whether pathnames, or references to header files) are always in italics (e.g., <stdio.h>), except in the SYNOPSIS section, where included files are in bold (e.g., #include <stdio.h>). When referring to a standard header file include, specify the header file surrounded by angle brackets, in the usual C way (e.g., <stdio.h>).
Special macros, which are usually in uppercase, are in bold (e.g., MAXINT). Exception: don't boldface NULL.
When enumerating a list of error codes, the codes are in bold (this list usually uses the .TP macro).
Complete commands should, if long, be written as an indented line on their own, with a blank line before and after the command, for example
man 7 man-pagesIf the command is short, then it can be included inline in the text, in italic format, for example, man 7 man-pages. In this case, it may be worth using nonbreaking spaces ("\ ") at suitable places in the command. Command options should be written in italics (e.g., -l).
Expressions, if not written on a separate indented line, should be specified in italics. Again, the use of nonbreaking spaces may be appropriate if the expression is inlined with normal text.
Any reference to the subject of the current manual page should be written with the name in bold. If the subject is a function (i.e., this is a Section 2 or 3 page), then the name should be followed by a pair of parentheses in Roman (normal) font. For example, in the fcntl(2) man page, references to the subject of the page would be written as: fcntl(). The preferred way to write this in the source file is:
.BR fcntl ()
(Using this format, rather than the use of "\fB...\fP()"
makes it easier to write tools that parse man page source files.)
Any reference to another man page should be written with the name in bold, always followed by the section number, formatted in Roman (normal) font, without any separating spaces (e.g., intro(2)). The preferred way to write this in the source file is:
.BR intro (2)
(Including the section number in cross references lets tools like
man2html(1)
create properly hyperlinked pages.)
Control characters should be written in bold face, with no quotes; for example, ^X.
Aside from the well-known spelling differences, there are a few other subtleties to watch for:
.SS Unicode under Linux
| Term | Avoid using | Notes |
| bit mask | bitmask | |
| built-in | builtin | |
| Epoch | epoch |
For the UNIX Epoch (00:00:00, 1 Jan 1970 UTC)
|
| filename | file name | |
| filesystem | file system | |
| hostname | host name | |
| inode | i-node | |
| lowercase | lower case, lower-case | |
| pathname | path name | |
| pseudoterminal | pseudo-terminal | |
| privileged port | reserved port, system port | |
| real-time | realtime, real time | |
| run time | runtime | |
| saved set-group-ID | saved group ID, saved set-GID | |
| saved set-user-ID | saved user ID, saved set-UID | |
| set-group-ID | set-GID, setgid | |
| set-user-ID | set-UID, setuid | |
| superuser | super user, super-user | |
| superblock | super block, super-block | |
| timestamp | time stamp | |
| timezone | time zone | |
| uppercase | upper case, upper-case | |
| usable | useable | |
| user space | userspace | |
| username | user name | |
| zeros | zeroes |
See also the discussion Hyphenation of attributive compounds below.
| Avoid | Use instead | Notes |
| 32bit | 32-bit |
same for 8-bit, 16-bit, etc.
|
| current process | calling process |
A common mistake made by kernel programmers when writing man pages
|
| manpage | man page, manual page | |
| minus infinity | negative infinity | |
| non-root | unprivileged user | |
| non-superuser | unprivileged user | |
| nonprivileged | unprivileged | |
| OS | operating system | |
| plus infinity | positive infinity | |
| pty | pseudoterminal | |
| tty | terminal | |
| Unices | UNIX systems | |
| Unixes | UNIX systems |
The preferred term for the pointer is "null pointer" or simply "NULL"; avoid writing "NULL pointer".
The preferred term for the byte is "null byte". Avoid writing "NUL", since it is too easily confused with "NULL". Avoid also the terms "zero byte" and "null character". The byte that terminates a C string should be described as "the terminating null byte"; strings may be described as "null-terminated", but avoid the use of "NUL-terminated".
BROWSER=firefox man -H pagename
The only place where such abbreviations may be acceptable is in short parenthetical asides (e.g., like this one).
Always include periods in such abbreviations, as shown here. In addition, "e.g." and "i.e." should always be followed by a comma.
32-bit value
command-line argument
floating-point number
run-time check
user-space function
wide-character string
interprocess
multithreaded
multiprocess
nonblocking
nondefault
nonempty
noninteractive
nonnegative
nonportable
nonzero
preallocated
precreate
prerecorded
reestablished
reinitialize
rearm
reread
subcomponent
subdirectory
subsystem
Hyphens should be retained when the prefixes are used in nonstandard English words, with trademarks, proper nouns, acronyms, or compound terms. Some examples:
non-ASCII
non-English
non-NULL
non-real-time
Finally, note that "re-create" and "recreate" are two different verbs, and the former is probably what you want.
\-
This guideline applies also to code examples.
\(aqC\(aq
where C is the quoted character. This guideline applies also to character constants used in code examples.
exit(EXIT_SUCCESS);
exit(EXIT_FAILURE);
Avoid using the following forms to terminate a program:
exit(0);
exit(1);
return n;
.SS Program source
Always do this if the explanatory text includes a shell session log.
If you include a shell session log demonstrating the use of a program or other system feature:
For some examples of what example programs should look like, see wait(2) and pipe(2).