Understanding masks

Masks are used to determine if a string matches specified pattern. Ad Annihilator uses masks for resource address recognition in banner, popup and cookie filters and for document and resource search .

A mask is a single sequence of characters that describe multiple matching strings at once. The mask serves as a template for matching a character pattern to the string being searched. There are two categories of characters:

• Special characters that have special meaning within masks and match a group of characters;

• Ordinary characters (for example letters a through z) and match only a single character.

Note that mask characters are case-insensitive. For example a*bc and A*Bc masks are equivalent.

Special characters

Special characters are listed in the following table:

The wildcard characters * (asterisk) ? (question mark) and [ (opening bracket) can match themselves only if enclosed in brackets.

See Examples for more usage examples.

Ordinary characters

Ordinary characters are all characters that do not belong to special characters. In the mask they match only itself. For example "mouse" mask matches only string "mouse" as it contains only ordinary characters.

Examples

Practical usage examples are detailed in the following table: