Capture groups and substitution patterns
Capture groups allow you to capture incoming information from the source URL, while substitution patterns allow you to refer to those capture groups in the modified URL. Substitution patterns use the back slash character (“\”) followed by a number to refer to the capture groups. For example, \1 is the first capture group, \2 is the second, etc.
The following diagram shows how you can set up numbered capture groups on parts of an inbound URL for Edge Redirector.