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This is a good reply. Everyone gets really confused because Robots.txt has very minor, partial wildcard support and that makes people think that Robots.txt files use Regex, which they do not. Instead of having some weird half and half implementation, it would be much better IMO if the Robots.txt initiative / directive were updated to say "yes, you can use full regular expressions with regards to URL string matching". Many people are left in a kind of silly guessing game because Google doesn't 'properly' elaborate or invest in expanding the definitions to their currently (publicly) assumed end-game. People assume that if "*" will match any string of characters, "?" will match any individual character when used in a robots.txt file. This would make sense, but it's not the case. AFAIK there are only one or two supported wildcard characters in Robots.txt and that's why people get confused, looking for escape characters and the suchlike.