Best results in other decks

You can write regular expressions some different ways, e.g. /regex/ and %r{regex}. For examples, look here. Remember that it is always a good idea to match a regex visually...

Alternation cat|dog will match cat in "About cats and dogs", if RegEx is applied again, it will match dog Quantifiers ? none or one, e.g. colou?r matches...

When you repeat a subpattern with a *, + or {...} operator, you may choose between greedy, lazy and possessive modes. Switching modes...