bug#24369: Docu of prefix-numeric-value

[Drew Adams]

> > What "treatment" are you asking to be explained?
> > Just what do you think is missing?
> 
> Elisp Info 20.2.2 Code Characters for ‘interactive’
> ----------------------------------------
> 
> p  The numeric prefix argument
> 
> Likewise with uppecase P.

Again, what do you think is missing?  `p' is the numeric prefix argument.
`P' is the raw prefix argument.

This is not the Elisp manual node that describes WHAT these things
are.  But there is a link here to the node that does that, node
`Prefix Command Arguments'

http://www.gnu.org/software/emacs/manual/html_node/elisp/Prefix-Command-Arguments.html

And that's the case even in the Emacs 20 version of the manual,
which you cited.

> User will expect the argument received by function being consistent with
> input, i.e. M-x 2 foo... sends 2, M-x 1 foo ... sends 1. From there
> omitting an argument will be expected to send nothing - which isn't the
> case.

Why on Earth would the user expect that, simply from reading that
`interactive' code `p' returns the numeric prefix argument and `P'
returns the raw prefix argument?