# 18 Regular expressions

Complex regular expressions can be created and tested in the Zabbix
frontend by going to Administration → General → [Regular
expressions](/manual/web_interface/administration#regular_expressions).

#### Using regular expressions

After a regular expression has been created, it can be used everywhere
regular expressions are supported by referring to it's name, prefixed
with **@**, for example, *\@mycustomregexp*.

#### Regular expression types

All regular expressions in Zabbix, whether created with the advanced
editor, or entered manually, support [POSIX extended regular
expressions](http://en.wikipedia.org/wiki/Regular_expression#POSIX_Extended_Regular_Expressions).