# Exim 4 Documentation

The following Exim 4 documentation is available in HTML:

- The full Exim 4 specification
- Specification of Exim's filtering facilities
- The Exim 4 FAQ

Also available in this documentation bundle are the following two PCRE documents:

- Specification PCRE regular expressions
- Specification of the pcretest program

A full description of the regular expressions that Exim supports is given in the first of them.