Regular Expression Metacharacters

. (dot)	Any one character
[...] [.-.]	Any one of the characters within the square brackets or within range
[^...]	Any one of the characters not within the square brackets
^	Start of line
$	End of line
\<	Start of word
/>	End of word
| (vertical bar)	Separates two expressions, matches either
?	Previous character (or group) is optional
+	One or more of the previous character (or group)
*	Any number (including none) of the previous character (or group) NOTE: Matches as many as possible
( )	Three uses: 1: Used to enclose a pair of expressions, separated by | (vertical bar - see above) 2: Grouping for quantifiers ('?', '+', and '*' - see above) 3: Carry some text that matches the expression within (see '\1', etc, below)
\1 (and \2, \3, etc)	Output the text 'carried forward' by the brackets (see '( )' above).
\ (backward slant)	Escape character except when as used above. The character that immediately follows a \ will be interpreted as a literal.