version.4th —
    FreeBSD version string boot module
The file that goes by the name of
    version.4th is a set of commands designed to draw
    the boot loader version at the bottom-right of the screen. The commands of
    version.4th by themselves are not enough for most
    uses. Please refer to the examples below for the most common situations, and
    to
    loader(8)
    for additional commands.
Before using any of the commands provided in
    version.4th, it must be included through the
    command:
include version.4th
This line is present in the default
    /boot/menu.rc file, so it is not needed (and should
    not be re-issued) in a normal setup.
The commands provided by it are:
  print_version 
  - Prints the contents of the loader_version
      environment variable right-justified at the column
      loader_version_x and row
      loader_version_y.
 
 
The environment variables that effect its behavior are:
  - loader_version
 
  - Set automatically by
      loader(8),
      but you can override it by setting in
      loader.conf(5).
      This should be the version of boot loader used.
 
  - loader_version_x
 
  - Sets the desired ending column position of
      loader_version. Default is 80.
 
  - loader_version_y
 
  - Sets the desired ending row position of
      loader_version. Default is 24.
 
  - loader_color
 
  - If set to “
NO” (case-insensitive) or
      “0”, causes the version to be
      printed without color (default is ANSI Cyan). 
 
  - /boot/loader
 
  - The
      loader(8).
 
  - /boot/version.4th
 
  version.4th itself. 
  - /boot/loader.rc
 
  - loader(8)
      bootstrapping script.
 
The version.4th set of commands first
    appeared in FreeBSD 9.0.
The version.4th set of commands was
    written by Devin Teske
    ⟨dteske@FreeBSD.org⟩.