/usr/lib/*tmac

  
$ cat t1.an 
.\" This is how you put comments
.TH "FooBar"
.SH "NAME"
FooBar
.SH "SYNOPSIS"
FooBar --help
.SH "DESCRIPTION"
Does nothing.

• .TH - the man page title
• .SH - section headers
• .SS - sub-section headers
• .P - new paragraph
• .br = Break line
• .B - bold text
• .I - text in italics
• 0 - header files
• 1 - standard user commands (and deamons)
• 2 - Linux kernel system calls
• 3 - standard c library functions
• 4 - special devices
• 5 - configuration files, formats and conventions
• 6 - games and toys
• 7 - miscellaneous , for example standards (for example SQL and ISO)
• 8 - root commands (and deamons)
• 9 - kernel details

   
  $ man ./t1.an
  
  $ nroff -man ./t1.an
  # see also groff, troff
  
  $ cp t1.an /usr/local/man/man1/t1.1