Your example isn't 100% clear about which of the test cases have valid data and which don't. One way to make things clearer is to allow for (and ignore) comment lines: 
  while ( <DATA> ) {
      next if /^(?:#.*|\s*)$/;
      ...
   }
   __DATA__
   # These should pass
   TAG:"test of data"
   ...
   # These should fail
   TAG: test
   ...

[download]
That saves us from having to guess, and removes the risk of our guessing wrong.

In reply to Re: Alternation in pattern matches by dws
in thread Alternation in pattern matches by guha

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