Hello, In older versions of squid, I was able to block or allow specific arbitrary request headers. For example: header_access X-SomeRandomHeaderA allow all header_access X-SomeRandomHeaderB deny all In squid-3.1 (and 3.0, I think), the equivalent of header_access for request headers is now request_header_access. But if I try this, squid gets upset and doesn't start: request_header_access X-SomeRandomHeaderA allow all request_header_access X-SomeRandomHeaderB deny all It says: 2010/03/16 13:55:19| parse_http_header_access: unknown header name 'X-SomeRandomHeaderA' So, it seems that you can only add headers that squid knows about internally. Which is what this page says: http://www.squid-cache.org/Doc/config/request_header_access/ You can only specify known headers for the header name. Other headers are reclassified as 'Other'. You can also refer to all the headers with 'All'. I could use 'Other', but it means that I have to treat all unknown headers in the same way. Unless I'm missing something. So, can anybody tell me how to block or allow specific arbitrary request headers in squid-3.1? Thank you.