While looking at (ice-9 r5rs), (ice-9 safe-r5rs)
and (ice-9 null), I've noticed, that there are a few
undocumented procedures used there, like
"make-module" or "set-module-kind!". In the thread
there is another one mentioned, named "beautify-user-module!".
Using the readline's completion feature, I also noticed
that there are procedures "module-obarray",
"module-observe", "make-modules-in" and some
others that are lacking an entry in the manual.
Are there any deeper reasons behind their absence,
or is it just an oversight?