System, method and program product performed by a proxy server which forwards an access request from a client to a data server and forwards response data from the data server to the client. A first address location and an encoding format of the response data are stored. A subsequent access request from the client which includes a second address location encoded by the encoding format is received. The second address location is compared to the first address location to determine if the second address location is related to the first address location. In response to a determination that the second address location is related to the first address location, the second address location is decoded based on the encoding format. The data server can be a web server, the response data can be a web page, and the second address location can include the first address. For example, the second address location can be an extension of the first address location.