手冊頁最後一行（或頁腳）的約定是什麼

我想知道在哪裡可以找到有關聯機幫助頁最後一行的含義或約定的文件，通過聯機幫助頁查找 man 沒有幫助。例如：

…$ man top|tail -n 1
procps-ng                       July 2014                          TOP(1)

…$ man rm|tail -n 1
GNU coreutils 8.25               February 2017                           RM(1)

關於 TOP 命令：

• procps-ng：這是 top 命令所屬的模組或工具系列嗎？
• 2014 年 7 月：這是編寫文件的日期還是此版本 top 的發布日期？
• TOP(1)：我猜這是對手冊頁本身的自我引用。

假設它是在 Linux 上使用 GNU 工俱生成的，則頁眉和頁腳都被一起指定為.TH宏的參數。來自man 7 groff_man：

.TH title section
  [footer-middle] [footer-outside] [header-middle] Define the
 title of the man page as title and the section as section.
 See man(1) for details on the section numbers and suffixes
 applicable to your system.  title and section are positioned
 together at the left and right in the header line (with
 section in parentheses immediately appended to title).
 footer-middle is centered in the footer line.  footer-outside
 is positioned at the left in the footer line (or at the left
 on even pages and at the right on odd pages if double-sided
 printing is active).  header-middle is centered in the header
 line.  If section is a simple integer between 1 and 9
 (inclusive), or is exactly “3p”, there is no need to specify
 header-middle; the macro package will supply text for it.

公約的其餘部分在man 7 man-pages：

Title line
  The first command in a man page should be a TH command:

         .TH title section date source manual

  where:
         title     The title of the man page, written in all caps
                   (e.g., MAN-PAGES).

         section   The section number in which the man page should be
                   placed (e.g., 7).

         date      The date of the last nontrivial change that was made
                   to the man page.  (Within the man-pages project, the
                   necessary updates to these timestamps are handled
                   automatically by scripts, so there is no need to
                   manually update them as part of a patch.)  Dates
                   should be written in the form YYYY-MM-DD.

         source    The source of the command, function, or system call.

                   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.

         manual    The title of the manual (e.g., for Section 2 and 3
                   pages in the man-pages package, use Linux
                   Programmer's Manual).

引用自：https://unix.stackexchange.com/questions/531153