Issues with the autobook documentation

• 22.2.1 Size Limitations,
  "Quite a lot of the Unix vendor implementations of the Bourne shell
  have a fixed buffer for storing command lines, as small as 512 characters"
  ... "sh: error: line too long"

  There was never any bourne shell with limits like that, it's the kernel.
  The smallest relevant limit (V7 kernel) was 5120 (by the way, POSIX guarantees 4096)

• 22.2.3 :,
  "Most Unices [...] will correctly pass a file with a single colon
  as its first line to `/bin/sh' for interpretation."

  Only csh does so, which is not relevant for scripting.
  And this is in no way related to a Unix (or its kernel) but only to the respective shell.

• 22.2.4 (),
  "There are still a great number of shells that,
  like Steve Bourne's original implementation, do not have functions!"

  Nowadays it's AFAIK only Ultrix (and only /bin/sh but not /bin/sh5).
  And Ultrix is becoming rare. In practice you can rely on functions (that is, a SVR2 shell).

• 22.2.7 $,
  "The unset command is not available in many of the degenerate Bourne shell implementations"

  The former item applies here, too.
  And there is no point about using degenerate, because Bourne shells without unset (or functions)
  are just quite early versions; they're not buggy or castrated about this.

• 22.2.8 * versus .*,
  "expr [...] is often(footnote 52) a shell builtin"
  "(footnote 52) Notable exceptions are GNU Bash, and both Ksh and the Bourne shell"

  What shells do come with an expr built-in?
  (I only know the very original release of the Almquist shell.
  Bash, ksh, traditional bourne shell, zsh, all later ash releases and pdksh don't provide it.)

• 22.3 Environment,
  "without LC_MESSAGES=C, Solaris will translate variable values in set!"

  What is meant? I can't reproduce something like that with SunOS 5.[1|3|5|6].