**What is a regular expression**

A regular expression is a language for specifying patterns that match a sequence of characters. Regular expressions consist of normal characters, which match the same character in the input. The following link is a great cheat sheet to help you learn all about different regular expression syntaxes:

http://www.addedbytes.com/cheat-sheets/download/regular-expressions-cheat-sheet-v1.pdf

We have also provided below some commonly used regular expressions to help you:

**Regular Expression Example 1 - Find links with no www or http**

To have autolinks find web links with no www or http you will need to use a regular expression.

An example of such a regular expression is the following:

Expression: .*?([^ ]*(\.com|\.net|\.org|\.co.uk|\.edu)).*?

Link: ##1##

You can modify this regular expression to fit your needs.

**Regular Expression Example 2 - Find ISBN Numbers on a publication**

To have autolinks find some ISBN numbers on your publication try the following regular expression:

Example ISBN: 123-1-12345-123-1

Expression: .*?(([0-9]{3})-([0-9]{1})-([0-9]{5})-([0-9]{3})-([0-9]{1})).*?

Link: http://www.site.com/catalogue.asp?isbn=##2####3####4####5####6##

You may need to modify this regular expression to fit your needs or your ISBN number style

**Regular Expression Example 3 - Find product code on a publication**

To have autolinks find a sample five character product code on your publication try the following regular expression:

Example Product code: ABC-123

Expression: .*([A-Z0-9]{3})(-)([A-Z0-9]{3}\b).*

Link: http://www.site.com/catalogue.asp?prodid=##1##

You may need to modify this regular expression to fit your needs or your product code number style

**Regular Expression Example 4 - Finding random numbers of xxxxx**

To have autolinks find a sequence of five random numbers try the following regular expression:

Example: 12345

Expression: .*([0-9]{5}\b).*

Link: http://www.site.com/catalogue.asp?code=##1##

**Regular Expression Example 5 - Finding numeric codes of xxx-xxxxx**

To have autolinks find a sequence of numeric codes try the following regular expression:

Example: 123-12345

Expression: .*([0-9]{3}(-)[0-9]{5}\b).*

Link: http://www.site.com/catalogue.asp?code=##1##

**Regular Expression Example 6 - Finding numeric codes (with a space) of xxx xxxxx**

To have autolinks find a sequence of numeric codes try the following regular expression:

Example: 123 12345

Expression: .*([0-9]{3}()[0-9]{4}\b).*

Link: http://www.site.com/catalogue.asp?code=##1##

**Regular Expression Example 7 - Finding email addresses**

To have autolinks find a sequence of numeric codes try the following regular expression:

Example: test@test.com

Expression: .*?([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}).*?

Link: mailto:##1##

**Regular Expression Example 8 - Finding fixed number codes 12345**

To have autolinks find a sequence of numeric codes try the following regular expression:

Example: 12345

Expression: .*(\<12345 \>).*

Link: http://www.site.com/catalogue.asp?code=##1##

**Regular Expression Example 9 - Finding specific words**

To have autolinks find a sequence of numeric codes try the following regular expression:

Example: zmags

Expression: .*(\<zmags \>).*

Link: http://www.site.com/catalogue.asp?word=##1##

**Regular Expression Example 10 - Finding numbers and letters**

To have autolinks find a sequence of numbers and letters try the following regular expression:

Example: 1234AB1234

Expression: .*(\b[0-9-A-Z]{12}\b).*

Link: http://www.site.com/catalogue.asp?id=##1##