I didn't like this as well, but I added it since that exact text appears in
the docstrings of many major modes. I though it was something like an
unwritten convention, but I guess many people have simply been copy-pasting
the same code over the years.  I'll have it removed.


On 4 November 2013 18:43, Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> > +Entry to this mode calls the value of `ruby-mode-hook'
> > +if that value is non-nil."
>
> That's problematic:
> - it's redundant since define-derived-mode already adds "In addition to
>   any hooks its parent mode `prog-mode' might have run,\nthis mode runs
>   the hook `ruby-mode-hook', as the final step\nduring initialization."
> - hooks aren't "called" but are "run".
> - it's not just "the value of `ruby-mode-hook'", but the *values*, since
>   hooks use both the buffer-local and the global value of the symbol.
> - the hook is run even if it is nil (or unbound): running it will simply
>   not do anything.
>
>
>         Stefan
>