"special" keys understood by `kbd' (aka `read-kbd-macro', aka `edmacro-parse-keys')

[Miles Bader]

If the `kbd' function is given "RET" (or "<RET>") it returns "^M", since
`RET' is emacs' user-friendly name for carriage return.

It also does this for the following keys:

  "\\<\\(NUL\\|RET\\|LFD\\|ESC\\|SPC\\|DEL\\)$"

However, it *doesn't* do so for TAB (it just returns it as a function
key), which is odd, because the same file *prints* a tab as "TAB".

Is this an oversight, or is there some reason?

-Miles