Regular expressions
You can use regular expressions to filter data by URL.
The expression is processed according to RE2 syntax and the following rules:
 The regular expression is applied to the page's full URL, including protocol and domain. For example, you can use the regular
expression:
^http://
.  The regular expression is applied twice: first to the original URL, and then to the URL with and without the
www
prefix. This means that the results do not depend on whether thewww
prefix is included in the domain.  The regular expression is applied to the decoded URL, in which URL escape codes (% sequences) are replaced with decoded characters
(exception: character codes
/
,&
,=
,?
,#
are not replaced; for example,%2F
will not be replaced with/
). It is important to bear in mind that the plus sign (+
) is replaced with a space when decoding. For example, the regular expressiontext=elephant
will be processed, buttext=%D1%81%D0%BB%D0%BE%D0%BD
andtext=%\w\w
will not.  Punycode is not applied to Cyrillic URLs. For example, the regular expression
^http://ввв\.сайт\.рф/
will be processed, but^http://xnb1aaa\.xn80aswg\.xnp1ai/
will not.  Before checking regular expressions, certain symbols are removed from the end of the URL:
?
,#
,&
, and the dot (.
). For example, for the URLshttp://example.com/?
,http://example.com/#
, andhttp://example.com/?var=1&
, the comparison will be made withhttp://example.com/
,http://example.com/
, andhttp://example.com/?var=1
, respectively. If the user enters the URLhttp://example.com./
, the regular expression\./$
will not be processed.  When checking regular expressions, the characters in URLs are casesensitive.
 Quantifiers match the longest possible string when checking expressions.
Instructions on regular expressions
In the table below, a
, b
, c
, d
, and e
are any characters, and n
and m
are whole positive integers.
Alternative variants  

abcde  Matches one of the variants: abc or de .

Character classes  
[abc] or [ac]  Matches any (one) character from those listed (or from the range). 
[^abc] or [^ac]  Matches any (one) character that is not listed (or does not fall within the range). 
\d  Matches a digit. Equivalent to [09] .

\D  Matches a nondigit. Equivalent to [^09] .

\s  Matches a space. Equivalent to [\t\n\f\r ] .

\S  Matches any character that is not a space. Equivalent to [^\t\n\f\r ] .

\pL  Matches any Unicode character. 
\w 
Matches an uppercase or lowercase Latin letter, number, or underscore. When working with Unicode characters, use the 
\W 
Matches any character that is not an uppercase or lowercase Latin letter, number, or underscore. When working with Unicode characters, use the 
Number of occurrences (quantifiers)  
a*  Matches the character a repeated 0 or more times (the longest of possible sequences is selected).

a+  Matches the character a repeated 1 or more times (the longest of possible sequences is selected).

a?  Matches the character a repeated 0 or 1 time (priority is given to the character's occurrence).

a{n,m}  Matches the character a repeated no less than n and no more than m times (the longest of possible sequences is selected).

a{n,}  Matches the character a repeated no less than n times (the longest of possible sequences is selected).

a{n}  Matches the character a repeated exactly n times.

a*?  Matches the character a repeated 0 or more times (the shortest of possible sequences is selected).

a+?  Matches the character a repeated 1 or more times (the shortest of possible sequences is selected).

a??  Matches the character a repeated 0 or 1 time (priority is given to the character's absence). 
a{n,m}?  Matches the character a repeated no less than n and no more than m times (the shortest of possible sequences is selected).

a{n,}?  Matches the character a repeated no less than n times (the shortest of possible sequences is selected).

Position within the string  
^  Matches the beginning of the string. 
$  Matches the end of the string. 
\b 
Matches a word boundary — the position between an alphanumeric character ( 
\B 
Matches the absence of a word boundary. Defined through the classes 
Escape sequences  
\ 
A backslash before one of the special characters Example: 
\Q...\E  All special characters in the interval between \Q and \E are interpreted as regular characters.

Alternative variants  

abcde  Matches one of the variants: abc or de .

Character classes  
[abc] or [ac]  Matches any (one) character from those listed (or from the range). 
[^abc] or [^ac]  Matches any (one) character that is not listed (or does not fall within the range). 
\d  Matches a digit. Equivalent to [09] .

\D  Matches a nondigit. Equivalent to [^09] .

\s  Matches a space. Equivalent to [\t\n\f\r ] .

\S  Matches any character that is not a space. Equivalent to [^\t\n\f\r ] .

\pL  Matches any Unicode character. 
\w 
Matches an uppercase or lowercase Latin letter, number, or underscore. When working with Unicode characters, use the 
\W 
Matches any character that is not an uppercase or lowercase Latin letter, number, or underscore. When working with Unicode characters, use the 
Number of occurrences (quantifiers)  
a*  Matches the character a repeated 0 or more times (the longest of possible sequences is selected).

a+  Matches the character a repeated 1 or more times (the longest of possible sequences is selected).

a?  Matches the character a repeated 0 or 1 time (priority is given to the character's occurrence).

a{n,m}  Matches the character a repeated no less than n and no more than m times (the longest of possible sequences is selected).

a{n,}  Matches the character a repeated no less than n times (the longest of possible sequences is selected).

a{n}  Matches the character a repeated exactly n times.

a*?  Matches the character a repeated 0 or more times (the shortest of possible sequences is selected).

a+?  Matches the character a repeated 1 or more times (the shortest of possible sequences is selected).

a??  Matches the character a repeated 0 or 1 time (priority is given to the character's absence). 
a{n,m}?  Matches the character a repeated no less than n and no more than m times (the shortest of possible sequences is selected).

a{n,}?  Matches the character a repeated no less than n times (the shortest of possible sequences is selected).

Position within the string  
^  Matches the beginning of the string. 
$  Matches the end of the string. 
\b 
Matches a word boundary — the position between an alphanumeric character ( 
\B 
Matches the absence of a word boundary. Defined through the classes 
Escape sequences  
\ 
A backslash before one of the special characters Example: 
\Q...\E  All special characters in the interval between \Q and \E are interpreted as regular characters.
