# Element: patterns ## Location /[patterndb](../../../../../docs/axosyslog-core/chapter-parsers/chapter-patterndb/reference-parsers-pattern-databases/reference-patterndb-schemes/patterndb-scheme-patterndb/index.md)/[ruleset](../../../../../docs/axosyslog-core/chapter-parsers/chapter-patterndb/reference-parsers-pattern-databases/reference-patterndb-schemes/patterndb-scheme-ruleset/index.md)/_patterns_ ## Description A container element. A `` element may contain any number of `elements. ## Attributes N/A ## Children * _pattern_ : The name of the application — syslog-ng matches this value to the ${PROGRAM} header of the syslog message to find the rulesets applicable to the syslog message. Specifying multiple patterns is useful if two or more applications have different names (that is, different ${PROGRAM} fields), but otherwise send identical log messages. It is not necessary to use multiple patterns if only the end of the ${PROGRAM} fields is different, use only the beginning of the ${PROGRAM} field as the `pattern`. For example, the Postfix email server sends messages using different process names, but all of them begin with the `postfix` string. You can also use parsers in the program pattern if needed, and use the parsed results later. For example: `stfix\@ESTRING:.postfix.component:[@» Note If the `element of a ruleset is not specified, AxoSyslog will use this ruleset as a fallback ruleset: it will apply the ruleset to messages that have an empty PROGRAM header, or if none of the program patterns matched the PROGRAM header of the incoming message. ## Example ``` firstapplication otherapplication ``` Using parsers in the program pattern: ``` postfix\@ESTRING:.postfix.component:[@ ``` Last modified July 2, 2023: [Change highlight mode of code examples (2f8a959)]()