But please note the second fOO

Yes, good point! I think the main question is what the intent of the regex is. If it's "replace any o's at the end of each line", then the better solution is, as you said, /o+$/, and using o* is the "mistake".

In reply to Re^4: You won't believe what this regular expression does! by haukex
in thread You won't believe what this regular expression does! by salva

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