^
\A
$
\Z
\b
\B
\<
\>
\c
\s
\S
\d
\D
\w
\W
\x
\O
[:upper:]
[:lower:]
[:alpha:]
[:alnum:]
[:digit:]
[:xdigit:]
[:punct:]
[:blank:]
[:space:]
[:cntrl:]
[:graph:]
[:print:]
[:word:]
?=
?!
?<=
?!= or ?
?>
?()
?()|
?#
*
+
?
{3}
{3,}
{3,5}
"x"
x?
\
\n
\r
\t
\v
\f
\xxx
\xhh
.
(a|b)
(...)
(?:...)
[abc]
[^abc]
[a-q]
[A-Q]
[0-7]
g
i
m
s
x
e
U
$n
$2
$1
$`
$'
$+
$&
([A-Za-z0-9-]+)
Letters, numbers and hyphens(\d{1,2}\/\d{1,2}\/\d{4})
Date (e.g. 21/3/2006)([^\s]+(?=\.(jpg|gif|png))\.\2)
jpg, gif or png image(^[1-9]{1}$|^[1-4]{1}[0-9]{1}$|^50$)
Any number from 1 to 50 inclusive(#?([A-Fa-f0-9]){3}(([A-Fa-f0-9]){3})?)
Valid hexadecimal colour code((?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,15})
String with at least one upper case letter, one lower case letter, and one digit (useful for passwords).^(([A-Za-z0-9]+_+)|([A-Za-z0-9]+\-+)|([A-Za-z0-9]+\.+)|([A-Za-z0-9]+\++))*[A-Za-z0-9]+@((\w+\-+)|(\w+\.))*\w{1,63}\.[a-zA-Z]{2,6}$
Email addresses(\<(/?[^\>]+)\>)
HTML Tags