This is what perldiag has to say:

Unquoted string "%s" may clash with future reserved word
(W) You used a bareword that might someday be claimed as a reserved word. It's best to put such a word in quotes, or capitalize it somehow, or insert an underbar into it. You might also declare it as a subroutine.

Use of reserved word "%s" is deprecated
(D) The indicated bareword is a reserved word. Future versions of perl may use it as a keyword, so you're better off either explicitly quoting the word in a manner appropriate for its context of use, or using a different name altogether. The warning can be suppressed for subroutine names by either adding a & prefix, or using a package qualifier, e.g. &our(), or Foo::our().

I sense a distinction between 'keyword' and 'reserved word'. All keywords are reserved words, but not all reserved words are keywords (yet).

I personally never found this confusing, but if you feel morally opposed to it, send a patch on over to P5P. :)

$_="goto+F.print+chop;\n=yhpaj";F1:eval