Using Regular Expression Metacharacters

Since Chameleon utilizes regular expressions for the Message Identity matching algorithm, you can use the metacharacters described in the table below for the matching rule:

Metacharacter	Description
^	Anchors match to the beginning of a line or string
$	Anchors match to the end of a line or string
abc	Matches all of a, b, and c in order
fee\|fie\|foe	Matches one of fee, fie, or foe
^(?!fee\|fie\|foe)	Matches anything other than fee, fie, or foe
.	Matches any character except newline
x?	Matches 0 or 1 occurrences of x (x can be any character)
x*	Matches 0 or more occurrences of x
x+	Matches 1 or more occurrences of x
x{m,n}	Matches at least m occurrences of x but no more than n
[a-z0-9]	Matches any single character of set
[^a-z0-9]	Matches any single character not in set
\d	Matches a digit, same as [0-9]
\D	Matches a non-digit, same as [^0-9]
\w	Matches an alphanumeric (word) character [a-zA-Z0-9_]
\W	Matches a non-word character [^a-zA-Z0-9_]
\s	Matches a whitespace character (space, tab, newline...)
\S	Matches a non-whitespace character
\metachar	Treat metacharacter as ordinary character; for example, \* matches the * character
(abc)	Remembers the match for later backreferences
\1	Matches whatever first set of parens matched
\2	Matches whatever second set of parens matched
\3	and so on...
\b	Matches a word boundary (outside [] only)
\B	Matches a non-word boundary


	Use the ^ and $ metacharacters around values that may be part of other values. For example, a value of 5 without anchors will also match with 15, 250, etc. To prevent it from matching with other values, place anchors around it: ^5$.

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Using Regular Expression Metacharacters