. Any char | \d Digit | \w Word char | \s Whitespace
\b Word boundary | ^ Start | $ End
* 0+ | + 1+ | ? 0 or 1 | {n,m} n to m
[abc] Char class | [^abc] Negated | (group) Capture
(?:nc) Non-capture | (?=la) Lookahead | (?<=lb) Lookbehind
a|b Alternation | (?<name>) Named group | \1 Backreference