Extension:AbuseFilter/Rules format/ha

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The rules are a custom language. They are formatted similar to conditionals in a C/Java/Perl-like language.

Strings

You can specify a literal by placing it in single or double quotes (for strings), or by typing it in as-is (for numbers, both floating-point and integer). You can get linebreaks with \n, tab characters with \t, and you can also escape the quote character with a backslash.

Use the + (plus) symbol to concatenate two literal strings or the values of two vars with a string value.

Examples

"This is a string"
'This is also a string'
'This string shouldn\'t fail'
"This string\nHas a linebreak"
1234
1.234
-123

User-defined variables

You can define custom variables for ease of understanding with the assign symbol := in a line (closed by ;) within a condition. Such variables may use letters, underscores, and numbers (apart from the first character) and are case-insensitive. Example (from w:Special:AbuseFilter/79):

(
	line1:="(\{\{(r|R)eflist|\{\{(r|R)efs|<references\s?/>|</references\s?>)";
	rcount(line1, removed_lines)
) > (
	rcount(line1, added_lines)
)

Arrays

AbuseFilter has support for non-associative arrays, which can be used like in the following examples.

Caution: Expressions like page_namespace in [14, 15] may not work as expected. This one will evaluate to true also if page_namespace is 1, 4, or 5. For more information and possible workarounds, please see T181024.

my_array := [ 5, 6, 7, 10 ];
my_array[0] == 5
length(my_array) == 4
int( my_array ) === 4 // Same as length
float( my_array ) === 4.0 // Counts the elements
string(my_array) == "5\n6\n7\n10\n" // Note: the last linebreak could be removed in the future
5 in my_array == true
'5' in my_array == true
'5\n6' in my_array == true // Note: this is due to how arrays are casted to string, i.e. by imploding them with linebreaks
1 in my_array == true // Note: this happens because 'in' casts arguments to strings, so the 1 is caught in '10' and returns true.
my_array[] := 57; // This appends an element at the end of the array
my_array === [ 5, 6, 7, 10, 57 ]
my_array[2] := 42; // And this is for changing an element in the array
my_array === [ 5, 6, 42, 10, 57 ]

Comments

You can specify comments using the following syntax:

/* This is a comment */

Arithmetic

You can use basic arithmetic symbols to do arithmetic on variables and literals with the following syntax:

- – Subtract the right-hand operand from the left-hand operand.
+ – Add the right-hand operand to the left-hand operand.
* – Multiply the left-hand operand by the right-hand operand.
/ – Divide the left-hand operand by the right-hand operand.
** – Raise the left-hand operand to the exponential power specified by the right-hand operand.
% – Return the remainder given when the left-hand operand is divided by the right-hand operand.

The type of the returned result is the same that would be returned by PHP, for which a lot of documentation may be found online. More exhaustive examples may be found in this AF parser test.

Example	Result
`1 + 1`	2
`2 * 2`	4
`1 / 2`	0.5
`9 ** 2`	81
`6 % 5`	1

Boolean operations

You can match if and only if all of a number of conditions are true, one of a number of conditions are true, or one and only one of all conditions are true.

x | y — OR – returns true if one or more of the conditions is true.

x & y — AND – returns true if both of the conditions are true.

x ^ y — XOR – returns true if one, and only one of the two conditions is true.

!x — NOT – returns true if the condition is not true.

Examples

Code	Result
`1 \| 1`	true
`1 \| 0`	true
`0 \| 0`	false
`1 & 1`	true
`1 & 0`	false
`0 & 0`	false
`1 ^ 1`	false
`1 ^ 0`	true
`0 ^ 0`	false
`!1`	false
`!0`	true

Simple comparisons

You can compare variables with other variables and literals with the following syntax:

<, > – Return true if the left-hand operand is less than/greater than the right-hand operand respectively. Watch out: operands are casted to strings and, like it happens in PHP, null < any number === true and null > any number === false.
<=, >= – Return true if the left-hand operand is less than or equal to/greater than or equal to the right-hand operand respectively. Watch out: operands are casted to strings and, like it happens in PHP, null <= any number === true and null >= any number === false.

== (or =), != – Return true if the left-hand operand is equal to/not equal to the right-hand operand respectively.

===, !== – Return true if the left-hand operand is equal to/not equal to the right-hand operand AND the left-hand operand is the same/not the same data type to the right-hand operand respectively.

Example	Result
`1 == 2`	false
`1 <= 2`	true
`1 >= 2`	false
`1 != 2`	true
`1 < 2`	true
`1 > 2`	false
`2 = 2`	true
`'' == false`	true
`'' === false`	false
`1 == true`	true
`1 === true`	false
`['1','2','3'] == ['1','2','3']`	true
`[1,2,3] === [1,2,3]`	true
`['1','2','3'] == [1,2,3]`	true
`['1','2','3'] === [1,2,3]`	false
`[1,1,''] == [true, true, false]`	true
`[] == false & [] == null`	true
`['1'] == '1'`	false^[1]

Built-in variables

The abuse filter passes various variables by name into the parser. These variables can be accessed by typing their name in, in a place where a literal would work. You can view the variables associated with each request in the abuse log.

Variables from AbuseFilter

Variables always available

Caution: User-related variables are always available, except for one case: account creation when the creator is not logged in. All variables starting with user_ are affected, except user_type.

Description	Name	Data type	Notes
Action	`action`	string	One of the following: edit, move, createaccount, autocreateaccount, delete, upload^[2], stashupload^[3]
Unix timestamp of change	`timestamp`	string	int(timestamp) gives you a number with which you can calculate the date, time, day of week, etc.
Database name of the wiki ($1)	`wiki_name`	string	For instance, this is "enwiki" on the English Wikipedia, and "itwikiquote" on the Italian Wikiquote.
Language code of the wiki ($1)	`wiki_language`	string	For instance, this is "en" on the English Wikipedia, and "it" on the Italian Wikiquote. Multi-lingual wikis like Commons, Meta, and Wikidata will also report as "en".
Edit count of the user ($1)	`user_editcount`	integer/null	Null only for unregistered users.
Name of the user account ($1) (IP in case the user is not registered)	`user_name`	string	For "createaccount" and "autocreateaccount" actions, use `accountname` if you want the name of the account being created.
Type of the user account ($1)	`user_type`	string	The type of the user, which will be one of `ip`, `temp` (if the user is using a temporary account ), `named`, `external`, or `unknown`.
Time email address was confirmed ($1)	`user_emailconfirm`	string/null	In the format: YYYYMMDDHHMMSS. Null if the email wasn't confirmed.
Age of the user account ($1)	`user_age`	integer	In seconds. 0 for unregistered users.
Whether the user is blocked ($1)	`user_blocked`	boolean	True for blocked registered users. Also true for edits from blocked IP addresses, even if the editor is a registered user who is not blocked. False otherwise. This doesn't differentiate between partial and sitewide blocks.
Groups (including implicit) the user is in ($1)	`user_groups`	array of strings	see Special:ListGroupRights
Rights that the user has ($1)	`user_rights`	array of strings	see Special:ListGroupRights
Page ID ($1)	`article_articleid`	integer	(deprecated) Use `page_id` instead.
Page ID ($1) (can be seen via "page information" link in sidebar)	`page_id`	integer	This is 0 for new pages, but it is unreliable when inspecting past hits. If you need an exact result when inspecting past hits, use "page_age == 0" to identify new page creation. (note that it is slower, though.) This issue has been fixed in 9369d08, merged on September 11th 2023.
Page namespace ($1)	`article_namespace`	integer	(deprecated) Use `page_namespace` instead.
Page namespace ($1)	`page_namespace`	integer	refers to namespace index . Check for namespace(s) using expressions like "page_namespace == 2" or "equals_to_any(page_namespace, 1, 3)"
Page age in seconds ($1)	`page_age`	integer	the number of seconds since the first edit (or 0 for new pages). This is reliable, but it tends to be slow; consider using `page_id` if you don't need much precision.
Page title without namespace ($1)	`article_text`	string	(deprecated) Use `page_title` instead.
Page title without namespace ($1)	`page_title`	string
Full page title ($1)	`article_prefixedtext`	string	(deprecated) Use `page_prefixedtitle` instead.
Full page title ($1)	`page_prefixedtitle`	string
Edit protection level of the page ($1)	`article_restrictions_edit`	string	(deprecated) Use `page_restrictions_edit` instead.
Edit protection level of the page ($1)	`page_restrictions_edit`	array of strings
Move protection level of the page ($1)	`article_restrictions_move`	string	(deprecated) Use `page_restrictions_move` instead.
Move protection level of the page ($1)	`page_restrictions_move`	array of strings
Upload protection of the file ($1)	`article_restrictions_upload`	string	(deprecated) Use `page_restrictions_upload` instead.
Upload protection of the file ($1)	`page_restrictions_upload`	array of strings
Create protection of the page ($1)	`article_restrictions_create`	string	(deprecated) Use `page_restrictions_create` instead.
Create protection of the page ($1)	`page_restrictions_create`	array of strings
Last ten users to contribute to the page ($1)	`article_recent_contributors`	array of strings	(deprecated) Use `page_recent_contributors` instead.
Last ten users to contribute to the page ($1)	`page_recent_contributors`	array of strings	This tends to be slow (see #Performance). Try to put conditions more likely evaluate to false before this one, to avoid unnecessarily running the query. This value is empty if the user is the only contributor to the page(?), and only scans the last 100 revisions
First user to contribute to the page ($1)	`article_first_contributor`	string	(deprecated) Use `page_first_contributor` instead.
First user to contribute to the page ($1)	`page_first_contributor`	string	This tends to be slow (see #Performance).^[4] Try to put conditions more likely evaluate to false before this one, to avoid unnecessarily running the query.

Variables available for some actions

Caution: Always check that the variables you want to use are available for the current action being filtered, e.g. by using the action variable. Failing to do so (for instance using accountname for an edit, or edit_delta for a deletion) will make any code using the variable in question return false.

Edit variables are not available when examining past uploads. (T345896)

Description	Name	Data type	Notes
Edit summary/reason ($1)	`summary`	string	Summaries automatically created by MediaWiki ("New section", "Blanked the page", etc.) are created after the filter checks the edit, so they will never actually catch, even if the debugger shows that they should. The variable contains whatever the user sees in the edit summary window, which may include MediaWiki preloaded section titles.^[5]
~~Whether or not the edit is marked as minor (no longer in use)~~	~~`minor_edit`~~	~~string~~	Disabled, and set to false for all entries between 2016 and 2018.^[6]
Old page wikitext, before the edit ($1)	`old_wikitext`	string	This variable can be very large. Consider using `removed_lines` if possible to improve performance.
New page wikitext, after the edit ($1)	`new_wikitext`	string	This variable can be very large. Consider using `added_lines` if possible to improve performance.
Unified diff of changes made by edit ($1)	`edit_diff`	string
Unified diff of changes made by edit, pre-save transformed ($1)	`edit_diff_pst`	string	This tends to be slow (see #Performance). Checking both `added_lines` and `removed_lines` is probably more efficient.^[7]
New page size ($1)	`new_size`	integer
Old page size ($1)	`old_size`	integer
Size change in edit ($1)	`edit_delta`	integer
Lines added in edit, pre-save transformed ($1)	`added_lines_pst`	array of strings	Use `added_lines` if possible, which is more efficient.
Lines added in edit ($1)	`added_lines`	array of strings	includes all lines in the final diff that begin with +
Lines removed in edit ($1)	`removed_lines`	array of strings
All external links in the new text ($1)	`all_links`	array of strings	This tends to be slow (see #Performance).
Links in the page, before the edit ($1)	`old_links`	array of strings	This tends to be slow (see #Performance).
All external links added in the edit ($1)	`added_links`	array of strings	This tends to be slow (see #Performance). Consider checking against `added_lines` first, then check `added_links` so that fewer edits are slowed down. This follows MediaWiki's rules for external links . Only unique links are added to the array. Changing a link will count as 1 added and 1 removed link.
All external links removed in the edit ($1)	`removed_links`	array of strings	This tends to be slow (see #Performance). Consider checking against `removed_lines` first, then check `removed_links` so that fewer edits are slowed down. This follows MediaWiki's rules for external links . Only unique links are added to the array. Changing a link will count as 1 added and 1 removed link.
New page wikitext, pre-save transformed ($1)	`new_pst`	string	This variable can be very large.
Parsed HTML source of the new revision ($1)	`new_html`	string	This variable can be very large. Consider using `added_lines` if possible to improve performance.
New page text, stripped of any markup ($1)	`new_text`	string	This variable can be very large. Consider using `added_lines` if possible to improve performance.
~~Old page wikitext, parsed into HTML (no longer in use)~~	~~`old_html`~~	~~string~~	Disabled for performance reasons.
~~Old page text, stripped of any markup (no longer in use)~~	~~`old_text`~~	~~string~~	Disabled for performance reasons.
Time since last page edit in seconds ($1)	`page_last_edit_age`	integer or `null`	`null` when the page does not exist
SHA1 hash of file contents ($1)	`file_sha1`	string	^[2]
Size of the file in bytes ($1)	`file_size`	integer	The file size in bytes^[2]
Width of the file in pixels ($1)	`file_width`	integer	The width in pixels^[2]
Height of the file in pixels ($1)	`file_height`	integer	The height in pixels^[2]
Bits per color channel of the file ($1)	`file_bits_per_channel`	integer	The amount of bits per color channel^[2]
MIME type of the file ($1)	`file_mime`	string	The file MIME type.^[2]
Media type of the file ($1)	`file_mediatype`	string	The file media type.^[8]^[2]
Page ID of move destination page ($1)	`moved_to_articleid`	integer	(deprecated) Use `moved_to_id` instead.
Page ID of move destination page ($1)	`moved_to_id`	integer
Title of move destination page ($1)	`moved_to_text`	string	(deprecated) Use `moved_to_title` instead.
Title of move destination page ($1)	`moved_to_title`	string
Full title of move destination page ($1)	`moved_to_prefixedtext`	string	(deprecated) Use `moved_to_prefixedtitle` instead.
Full title of move destination page ($1)	`moved_to_prefixedtitle`	string
Namespace of move destination page ($1)	`moved_to_namespace`	integer
Move destination page age in seconds ($1)	`moved_to_age`	integer
Time since last move destination page edit in seconds ($1)	`moved_to_last_edit_age`	integer or `null`	`null` when the target page does not exist
Edit protection level of move destination page ($1)	`moved_to_restrictions_edit`	array of string	Same as `page_restrictions_edit`, but for the target of the move.
Move protection level of move destination page ($1)	`moved_to_restrictions_move`	array of string	Same as `page_restrictions_move`, but for the target of the move.
Upload protection of move destination file ($1)	`moved_to_restrictions_upload`	array of string	Same as `page_restrictions_upload`, but for the target of the move.
Create protection of move destination page ($1)	`moved_to_restrictions_create`	array of string	Same as `page_restrictions_create`, but for the target of the move.
Last ten users to contribute to move destination page ($1)	`moved_to_recent_contributors`	array of strings	Same as `page_recent_contributors`, but for the target of the move.
First user to contribute to move destination page ($1)	`moved_to_first_contributor`	string	Same as `page_first_contributor`, but for the target of the move.
Namespace of move source page ($1)	`moved_from_namespace`	integer
Title of move source page ($1)	`moved_from_text`	string	(deprecated) Use `moved_from_title` instead.
Title of move source page ($1)	`moved_from_title`	string
Full title of move source page ($1)	`moved_from_prefixedtext`	string	(deprecated) Use `moved_from_prefixedtitle` instead.
Full title of move source page ($1)	`moved_from_prefixedtitle`	string
Page ID of move source page ($1)	`moved_from_articleid`	integer	(deprecated) Use `moved_from_id` instead.
Page ID of move source page ($1)	`moved_from_id`	integer
Move source page age in seconds ($1)	`moved_from_age`	integer
Time since last move source page edit in seconds ($1)	`moved_from_last_edit_age`	integer
Edit protection level of move source page ($1)	`moved_from_restrictions_edit`	array of string	Same as `page_restrictions_edit`, but for the page being moved.
Move protection level of move source page ($1)	`moved_from_restrictions_move`	array of string	Same as `page_restrictions_move`, but for the page being moved.
Upload protection of move source file ($1)	`moved_from_restrictions_upload`	array of string	Same as `page_restrictions_upload`, but for the page being moved.
Create protection of move source page ($1)	`moved_from_restrictions_create`	array of string	Same as `page_restrictions_create`, but for the page being moved.
Last ten users to contribute to move source page ($1)	`moved_from_recent_contributors`	array of strings	Same as `page_recent_contributors`, but for the page being moved.
First user to contribute to move source page ($1)	`moved_from_first_contributor`	string	Same as `page_first_contributor`, but for the page being moved.
Account name on account creation ($1)	`accountname`	string
Content model of the old revision	`old_content_model`	string	See Help:ChangeContentModel for information about content model changes
Content model of the new revision	`new_content_model`	string	See Help:ChangeContentModel for information about content model changes

Masu canji masu kariya

Ana iya la'akari da mai canzawa a matsayin kariya. Misali, akan wikis tare da kunna asusun wucin gadi, ana ɗaukar IPs PII kuma dole ne a iyakance damar shiga su. Masu canji masu kariya da masu tacewa waɗanda ke amfani da su ana samun dama ga masu kiyayewa tare da abusefilter-access-protected-vars dama. Yin amfani da maɓalli mai kariya yana ba da tutocin tace kamar yadda aka kiyaye shi. Tace daga baya ba za ta iya zama mara kariya ba, koda kuwa ba ta ƙara yin amfani da maɓalli mai kariya ba, saboda rajistan ayyukansa na tarihi zai kasance da samuwa.

An fayyace ma'anar ma'auni na tsoho a cikin AbuseFilterProtectedVariables a cikin extension.json.

user_unnamed_ip is null when examining past edits.

Bayani	Suna	Nau'in bayanai	Bayanan kula
IP of the user account (for logged-out users and temporary accounts only) ($1)	`user_unnamed_ip`	kirtani	IP mai amfani don masu amfani da ba a san su ba/asusu na wucin gadi Wannan yana dawo da `null` ga masu amfani da rajista. Send feedback Side panels History Saved

Variables from other extensions

Most of these variables are always set to false when examinating past edits, and may not reflect their actual value at the time the edit was made. See T102944.


Description	Name	Data type	Values	Added by
Global groups that the user is in ($1)	`global_user_groups`	array		CentralAuth
Global edit count of the user ($1)	`global_user_editcount`	integer		CentralAuth
Global groups that the user is in on account creation ($1)	`global_account_groups`	array	Available only when `action` is `createaccount` (then it is always empty) or `autocreateaccount`.	CentralAuth
Global edit count of the user on account creation ($1)	`global_account_editcount`	integer	Available only when `action` is `createaccount` (then it is always zero) or `autocreateaccount`.	CentralAuth
OAuth consumer used to perform this change ($1)	`oauth_consumer`	integer		OAuth
Page ID of Structured Discussions board ($1)	`board_articleid`	integer	(deprecated) Use `board_id` instead.	StructuredDiscussions
Page ID of Structured Discussions board ($1)	`board_id`	integer		StructuredDiscussions
Namespace of Structured Discussions board ($1)	`board_namespace`	integer	refers to namespace index	StructuredDiscussions
Title (without namespace) of Structured Discussions board ($1)	`board_text`	string	(deprecated) Use `board_title` instead.	StructuredDiscussions
Title (without namespace) of Structured Discussions board ($1)	`board_title`	string		StructuredDiscussions
Full title of Structured Discussions board ($1)	`board_prefixedtext`	string	(deprecated) Use `board_prefixedtitle` instead.	StructuredDiscussions
Full title of Structured Discussions board ($1)	`board_prefixedtitle`	string		StructuredDiscussions
Source text of translation unit	`translate_source_text`	string		Translate
Target language for translation	`translate_target_language`	string	This is the language code, like `en` for English.	Translate
Whether or not the change was made through a Tor exit node ($1)	`tor_exit_node`	boolean	true if the action comes from a tor exit node.	TorBlock
Kodai ko a'a wani ma'aikaci yana gyara ta amfani da sigar wayar hannu	`user_mobile`	boolean	true for mobile users, false otherwise.	MobileFrontend
Whether the user is editing from mobile app ($1)	`user_app`	boolean	true if the user is editing from the mobile app, false otherwise.	MobileApp
Page views[1]	`article_views`	integer	(deprecated) Use `page_views` instead.	HitCounters
Page views[2]	`page_views`	integer	the amount of page views	HitCounters
Source page views[3]	`moved_from_views`	integer	the amount of page views of the source page	HitCounters
Target page views[4]	`moved_to_views`	integer	the amount of page views of the target page	HitCounters
Whether the IP address is blocked using the stopforumspam.com list[5]	`sfs_blocked`	boolean	Whether the IP address is blocked using the stopforumspam.com list	StopForumSpam

Notes

When action='move', only the summary, action, timestamp and user_* variables are available. The page_* variables are also available, but the prefix is replaced by moved_from_ and moved_to_, that represent the values of the original article name and the destination one, respectively. For example, moved_from_title and moved_to_title instead of page_title.

Since MediaWiki 1.28 (gerrit:295254), action='upload' is only used when publishing an upload, and not for uploads to stash. A new action='stashupload' is introduced, which is used for all uploads, including uploads to stash. This behaves like action='upload' used to, and only provides file metadata variables (file_*). Variables related to the page edit, including summary, new_wikitext and several others, are now available for action='upload'. For every file upload, filters may be called with action='stashupload' (for uploads to stash), and are always called with action='upload'; they are not called with action='edit'.

Filter authors should use action='stashupload' | action='upload' in filter code when a file can be checked based only on the file contents – for example, to reject low-resolution files – and action='upload' only when the wikitext parts of the edit need to be examined too – for example, to reject files with no description. This allows tools that separate uploading the file and publishing the file (e.g. UploadWizard or upload dialog ) to inform the user of the failure before they spend the time filling in the upload details.

Performance

As noted in the table above, some of these variables can be very slow. While writing filters, remember that the condition limit is not a good metric of how heavy filters are. For instance, variables like *_recent_contributors or *_links always need a DB query to be computed, while *_pst variables will have to perform parsing of the text, which again is a heavy operation; all these variables should be used very, very carefully. For instance, on Italian Wikipedia it's been observed that, with 135 active filters and an average of 450 used conditions, filters execution time was around 500ms, with peaks reaching 15 seconds. Removing the added_links variable from a single filter, and halving the cases when another filter would use added_lines_pst brought the average execution time to 50ms. More specifically:

Use _links variables when you need high accuracy and checking for "http://..." in other variables (for instance, added_lines) could lead to heavy malfunctioning;

Use _pst variables when you're really sure that non-PST variables aren't enough.

You may also conditionally decide which one to check: if, for instance, you want to examine a signature, check first if added_lines contains ~~~;

In general, when dealing with these variables, it's always much better to consume further conditions but avoid computing heavy stuff.

In order to achieve this, always put heavy variables as last conditions.

Last but not least, note that whenever a variable is computed for a given filter, it'll be saved and any other filter will immediately retrieve it. This means that one single filter computing this variable counts more or less as dozens of filters using it.

Keywords

Where not specifically stated, keywords cast their operands to strings

The following special keywords are included for often-used functionality:

like (or matches) returns true if the left-hand operand matches the glob pattern in the right-hand operand.
in returns true if the right-hand operand (a string) contains the left-hand operand. Note: empty strings are not contained in, nor contain, any other string (not even the empty string itself).
contains works like in, but with the left and right-hand operands switched. Note: empty strings are not contained in, nor contain, any other string (not even the empty string itself).
rlike (or regex) and irlike return true if the left-hand operand matches (contains) the regex pattern in the right-hand operand (irlike is case insensitive).
- The system uses PCRE.
- The only PCRE option enabled is PCRE_UTF8 (modifier u in PHP); for irlike both PCRE_CASELESS and PCRE_UTF8 are enabled (modifier iu).
if ... then ... end
if ... then ... else ... end
... ? ... : ...
true, false, null

Examples

Code	Result	Comment
`"1234" like "12?4"`	True
`"1234" like "12*"`	True
`"foo" in "foobar"`	True
`"foobar" contains "foo"`	True
`"o" in ["foo", "bar"]`	True	Due to the string cast
`"foo" regex "\w+"`	True
`"a\b" regex "a\\\\b"`	True	To look for the escape character backslash using regex you need to use either four backslashes or two `\x5C`. (Either works fine.)
`"a\b" regex "a\x5C\x5Cb"`	True

Functions

A number of built-in functions are included to ease some common issues. They are executed in the general format functionName( arg1, arg2, arg3 ), and can be used in place of any literal or variable. Its arguments can be given as literals, variables, or even other functions.

name	description
`lcase`	Returns the argument converted to lower case.
`ucase`	Returns the argument converted to upper case.
`length`	Returns the length of the string given as the argument. If the argument is an array, returns its number of elements.
`string`	Casts to string data type. If the argument is an array, implodes it with linebreaks.
`int`	Casts to integer data type.
`float`	Casts to floating-point data type.
`bool`	Casts to boolean data type.
`norm`	Equivalent to `rmwhitespace(rmspecials(rmdoubles(ccnorm(arg1))))`.
`ccnorm`	Normalises confusable/similar characters in the argument, and returns a canonical form. A list of characters and their replacements can be found on git, e.g. `ccnorm( "Eeèéëēĕėęě3ƐƷ" ) === "EEEEEEEEEEEEE"`.^[9] The output of this function is always uppercase. While not expensive, this function isn't cheap either, and could slow a filter down if called many times.
`ccnorm_contains_any`	Normalises confusable/similar characters in all its arguments, and returns true if the first string contains any string from the following arguments (unlimited number of arguments, logic OR mode). A list of characters and their replacements can be found on git. Due to the usage of `ccnorm`, this function can be slow if passed too many arguments.
`ccnorm_contains_all`	Normalises confusable/similar characters in all its arguments, and returns true if the first string contains every string from the following arguments (unlimited number of arguments, logic AND mode). A list of characters and their replacements can be found on git. Due to the usage of `ccnorm`, this function can be slow if passed too many arguments.
`specialratio`	Returns the number of non-alphanumeric characters divided by the total number of characters in the argument.
`rmspecials`	Removes any special characters in the argument, and returns the result. Does not remove whitespace. (Equivalent to s/[^\p{L}\p{N}\s]//g.)
`rmdoubles`	Removes repeated characters in the argument, and returns the result.
`rmwhitespace`	Removes whitespace (spaces, tabs, newlines).
`count`	Returns the number of times the needle (first string) appears in the haystack (second string). If only one argument is given, splits it by commas and returns the number of segments.
`rcount`	Similar to `count` but the needle uses a regular expression instead. Can be made case-insensitive by letting the regular expression start with "(?i)". Please note that, for plain strings, this function can be up to 50 times slower than `count`^[10], so use that one when possible.
`get_matches`	MW 1.31+ Looks for matches of the regex needle (first string) in the haystack (second string). Returns an array where the 0 element is the whole match and every `[n]` element is the match of the n'th capturing group of the needle. Can be made case-insensitive by letting the regular expression start with "(?i)". If a capturing group didn't match, that array position will take value of false.
`ip_in_range`	Returns true if user's IP (first string) matches the specified IP range (second string, can be in CIDR notation, explicit notation like "1.1.1.1-2.2.2.2", or a single IP). Only works for anonymous users. Supports both IPv4 and IPv6 addresses.
`ip_in_ranges`	Returns `true` if user's IP (first string) matches any of the specified IP ranges (following strings in logic OR mode, can be in CIDR notation, explicit notation like "1.1.1.1-2.2.2.2", or a single IP). Only works for anonymous users. Supports both IPv4 and IPv6 addresses.
`contains_any`	Returns true if the first string contains any string from the following arguments (unlimited number of arguments in logic OR mode). If the first argument is an array, it gets casted to string.
`contains_all`	Returns true if the first string contains every string from the following arguments (unlimited number of arguments in logic AND mode). If the first argument is an array, it gets casted to string.
`equals_to_any`	Returns true if the first argument is identical (`===`) to any of the following ones (unlimited number of arguments). Basically, `equals_to_any(a, b, c)` is the same as `a===b \| a===c`, but more compact and saves conditions.
`substr`	Returns the portion of the first string, by offset from the second argument (starts at 0) and maximum length from the third argument (optional).
`strlen`	Same as `length`.
`strpos`	Returns the numeric position of the first occurrence of needle (second string) in the haystack (first string), starting from offset from the third argument (optional, default is 0). This function may return 0 when the needle is found at the beginning of the haystack, so it might be misinterpreted as false value by another comparative operator. The better way is to use `===` or `!==` for testing whether it is found. Differently from PHP's strpos(), which returns false when the needle is not found, this function returns -1 when the needle is not found.
`str_replace`	Replaces all occurrences of the search string with the replacement string. The function takes 3 arguments in the following order: text to perform the search on, text to find, replacement text.
`str_replace_regexp`	Replaces all occurrences of the search string with the replacement string using regular expressions. The function takes 3 arguments in the following order: text to perform the search on, regular expression to match, replacement expression.
`rescape`	Returns the argument with some characters preceded with the escape character "\", so that the string can be used in a regular expression without those characters having a special meaning.
`set`	Sets a variable (first string) with a given value (second argument) for further use in the filter. Another syntax: `name := value`.
`set_var`	Same as `set`.

Examples

Code	Result	Comment
`length( "Wikipedia" )`	9
`lcase( "WikiPedia" )`	wikipedia
`ccnorm( "w1k1p3d14" )`	WIKIPEDIA	`ccnorm` output is always uppercase
`ccnorm( "ωɨƙɩᑭƐƉ1α" )`	WIKIPEDIA
`ccnorm_contains_any( "w1k1p3d14", "wiKiP3D1A", "foo", "bar" )`	true
`ccnorm_contains_any( "w1k1p3d14", "foo", "bar", "baz" )`	false
`ccnorm_contains_any( "w1k1p3d14 is 4w3s0me", "bar", "baz", "some" )`	true
`ccnorm( "ìíîïĩїį!ľ₤ĺľḷĿ" )`	IIIIIII!LLLLLL
`norm( "!!ω..ɨ..ƙ..ɩ..ᑭᑭ..Ɛ.Ɖ@@1%%α!!" )`	WIKIPEDAIA
`norm( "F00 B@rr" )`	FOBAR	`norm` removes whitespace, special characters and duplicates, then uses `ccnorm`
`rmdoubles( "foobybboo" )`	fobybo
`specialratio( "Wikipedia!" )`	0.1
`count( "foo", "foofooboofoo" )`	3
`count( "foo,bar,baz" )`	3
`rmspecials( "FOOBAR!!1" )`	FOOBAR1
`rescape( "abc* (def)" )`	abc\* $def$
`str_replace( "foobarbaz", "bar", "-" )`	foo-baz
`str_replace_regexp( "foobarbaz", "(.)a(.)", "$2a$1" )`	foorabzab
`ip_in_range( "127.0.10.0", "127.0.0.0/12" )`	true
`ip_in_ranges( "127.0.10.0", "10.0.0.0/8", "127.0.0.0/12" )`	true
`contains_any( "foobar", "x", "y", "f" )`	true
`get_matches( "(foo?ba+r) is (so+ good)", "fobaaar is soooo good to eat" )`	['fobaaar is soooo good', 'fobaaar', 'soooo good']

Order of operations

Operations are generally done left-to-right, but there is an order to which they are resolved. As soon as the filter fails one of the conditions, it will stop checking the rest of them (due to short-circuit evaluation) and move on to the next filter. The evaluation order is:

Anything surrounded by parentheses (( and )) is evaluated as a single unit.
Turning variables/literals into their respective data. (e.g., page_namespace to 0)
Function calls (norm, lcase, etc.)
Unary + and - (defining positive or negative value, e.g. -1234, +1234)
Keywords (in, rlike, etc.)
Boolean inversion (!x)
Exponentiation (2**3 → 8)
Multiplication-related (multiplication, division, modulo)
Addition and subtraction (3-2 → 1)
Comparisons (<, >, ==)
Boolean operations (&, |, ^)
Ternary operator (... ? ... : ...)
Assignments (:=)

Examples

A & B | C is equivalent to (A & B) | C, not to A & (B | C). In particular, both false & true | true and false & false | true evaluates to true.
A | B & C is equivalent to (A | B) & C, not to A | (B & C). In particular, both true | true & false and true | false & false evaluates to false.
added_lines rlike "foo" + "|bar" is wrong, use added_lines rlike ("foo" + "|bar") instead.

Condition counting

The condition limit is (more or less) tracking the number of comparison operators + number of function calls entered.

Further explanation on how to reduce conditions used can be found at Extension:AbuseFilter/Conditions .

Exclusions

Although the AbuseFilter examine function will identify "rollback" actions as edits, the AbuseFilter will not evaluate rollback actions for matching.^[11]

Useful links

Notes

↑ Comparing arrays to other types will always return false, except for the example above
↑ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 ^2.7 The only variables currently available for file uploads (action='upload') are user_*, page_*, file_sha1, file_size, file_mime, file_mediatype, file_width, file_height, file_bits_per_channel (the last five were only added since the release for MediaWiki 1.27 gerrit:281503). All the file_* variables are unavailable for other actions (including action='edit').
↑ Since MediaWiki 1.28 (gerrit:295254)
↑ Several filters (1 2) that use this variable have showed up in the AbuseFilterSlow Grafana dashboard (requires logstash access to view). Moving this variable to towards the end of the filter seemed to help.
↑ See phabricator:T191722
↑ Deprecated with this commit and disabled with this one.
↑ Some filters using this variable have showed up in the AbuseFilterSlow Grafana dashboard (example, requires logstash access). For instance, instead of using "text" in edit_diff_pst (or even edit_diff), consider something like "text" in added_lines & !("text" in removed_lines)
↑ See the source code for a list of types.
↑ Be aware of phab:T27619. You can use Special:AbuseFilter/tools to evaluate ccnorm( "your string" ) to see which characters are transformed.
↑ https://3v4l.org/S6IGP
↑ T24713 - rollback not matched by AF

[1] Comparing arrays to other types will always return false, except for the example above

[upload-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 ^2.7 The only variables currently available for file uploads (action='upload') are user_*, page_*, file_sha1, file_size, file_mime, file_mediatype, file_width, file_height, file_bits_per_channel (the last five were only added since the release for MediaWiki 1.27 gerrit:281503). All the file_* variables are unavailable for other actions (including action='edit').

[3] Since MediaWiki 1.28 (gerrit:295254)

[4] Several filters (1 2) that use this variable have showed up in the AbuseFilterSlow Grafana dashboard (requires logstash access to view). Moving this variable to towards the end of the filter seemed to help.

[5] See phabricator:T191722

[6] Deprecated with this commit and disabled with this one.

[7] Some filters using this variable have showed up in the AbuseFilterSlow Grafana dashboard (example, requires logstash access). For instance, instead of using "text" in edit_diff_pst (or even edit_diff), consider something like "text" in added_lines & !("text" in removed_lines)

[8] See the source code for a list of types.

[T27619-9] Be aware of phab:T27619. You can use Special:AbuseFilter/tools to evaluate ccnorm( "your string" ) to see which characters are transformed.

[10] ttps://3v4l.org/S6IGP

[11] T24713 - rollback not matched by AF

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