More examples with [Arg list not available until...]

[Markus Rost]

C-h f tex-mode 

yields for me the *Help* buffer:

=========
tex-mode is an interactive autoloaded Lisp function in `tex-mode'.
[Arg list not available until function definition is loaded.]

Not documented.
=========

After loading tex-mode.el I get the *Help* buffer:

=========
tex-mode is an interactive Lisp function in `tex-mode'.
(tex-mode)

Major mode for editing files of input for TeX, LaTeX, or SliTeX.
Tries to determine (by looking at the beginning of the file) whether
this file is for plain TeX, LaTeX, or SliTeX and calls `plain-tex-mode',
`latex-mode', or `slitex-mode', respectively.  If it cannot be determined,
such as if there are no commands in the file, the value of `tex-default-mode'
says which mode to use.

[back]
=========

I would have expected to see that *Help* buffer already before loading
tex-mode.el.  I am not sure what is a bug here and what is intended.
There seems to be a special handling of the derived-mode tex-mode.