Meta character Use/Meaning
. Match any character, except end-of-line (#x0D and/or #x0A) - same as [^\n\r]
\ Begin escape sequence
? Zero or one occurrences
* Zero or more occurrences
+ One or more occurrences
{ } Enclose a numeric quantifier or character group
( ) Enclose a regular expression (may be the atom of another regex)
[ ] Enclose a character class expression