Hi, We are using Squid 3.1 and need to do the following: 1. We have a list of URLs which we want to allow. 2. Squid to read this list of URLs and for each matching entry in the list, set a particular field (insert a string) in the HTTP header. 3. Using this header string, a URL filtering program will allow the URLs to be accessed. I explored the squid functionality and came across following: a. header_replace : Not sure how i can use this for my case. Examples and references are welcome. b. request_header_replace: Not available in 3.1. Not possible to upgrade to latest squid release. Is there any other option to do the same? Please suggest. Regards