It's hard to tell exactly what your validation criteria really are.
The way I hear it is, all the names in the array must be matched by the regex, or else there's a validation failure.

If all the names are single letters, as in your example, then the regex could look like this: /^[ABCDE]$/. That's known as a "character class".
However, if the names might be longer, e.g. qw/foo bar quux/, then the regex could use "alternation", like so: /^(foo|bar|quux)$/.

Then, to apply the regex (whichever way it's formulated), you could do this:

  my @failures = grep { !/$regex/ } @array;
  if ( @failures ) {
     warn "Validation failure.  Bad names: @failures\n";
  }
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Now, if what you're really wanting to do is ascertain that the given names are all in an "approved" set of names, a regex may not be the clearest way of implementing this. I'd recommend using a hash as a set, and using the exists function to determine set membership.

  my %valid_names;
  @valid_names{ qw/ A B C D E / } = (); # define the set of valid name
+s.

  my @failures = grep { ! exists $valid_names{$_} } @array;
  # and so forth.
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Of course, this only works neatly when the names are all exact. If there is any "fuzziness", such as what you might use wildcards for, then regexes are probably the way to go.

jdporter
The 6th Rule of Perl Club is -- There is no Rule #6.