Cisco TelePresence Administrator's Manual page 379

\ Escapes a regular expression special
character.
^ Signifies the start of a line.
When used immediately after an opening
brace, negates the character set inside the
brace.
$ Signifies the end of a line.
(?!...) Negative lookahead. Defines a
subexpression that must not be present.
(?<!...) Negative lookbehind. Defines a
subexpression that must not be present.
Note that regex comparisons are not case sensitive.
For an example of regular expression usage, see the
Cisco VCS Administrator Guide (X7.2)
[^abc] matches any single character that is NOT one
of a, b or c
^\d\d\d$ matches any string that is exactly 3 digits
long
(?!.*@example.com$).* matches any string that
does not end with @example.com
(?!alice).* matches any string that does not start
with alice
.*(?<!net) matches any string that does not end with
net
CPL examples section.
Reference material
Page 379 of 498