dear monks, I'm working on some text files in which the following pattern -=AB (for example) has to be marked with bold tags (for an html page). Moreover, the pattern may or not to be enclosed by square brackets. Thus I wrote the following simple regexp:

$line =~ s/-=(A)(\[|\])?(B)(\[|\])?/<b>$1$2$3<\/b>$4/g;

Well, it works fine, but the message "Use of uninitialized value in concatenation (.) or string ..." appears in the apache error log file. It, as far as I understand, depends on the fact that the backreference fields value are undefined whenever the square brackets miss into the pattern.
Of course, this really isn't good programming style but, that's my question, it is a real problem? Sould I correct it?

In reply to undefined backreferences by frasco

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
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