"Match Regular Expressions" is the second in the advertized list of features, but I don't know how to use these, and perhaps other users don't either. In any case I believe that different programming languages differ in the regular expressions they can interpret. Could a list of examples, at least, be provided under FAQs please? (Showing exactly what one would type into the edit box.)

...or at least a link to http://www.regular-expressions.info/quickstart.html which I've now found!