Regular expression

A regular expression (often shortened to regex) is a pattern that describes text, so that one rule can match many variations of it. colou?r matches both "color" and "colour", and ^https://shop\. matches addresses that begin with https://shop..

In Silktide, the rules of a policy offer Regular expression beside simpler choices such as Contains and Starts with. Use one only when those cannot say what you mean: a pattern that is slightly wrong can match far more, or far less, than you intended, so test it on a real page first.

Learn more

• Regular expressions (MDN) - a guide to the syntax
• Policies