This is nothing but some URL-encoded URI:
http://en.wikipedia.org/wiki/URL_encoding[
^]. As you can see, %28 and %29 encodes '(', and ')' character, which are nothing special, they are even valid file path characters in most file systems.
The second URI apparently uses URI parameters. The list of parameters starts with '?' and the parameters are delimited with '&'. This is a pretty sloppy way of passing some arbitrary parameters form a HTTP response (which could be simply an
anchor element in the referral page) to the requested page. Nevertheless, this technique is often used, even is some decent sites. Actually, it is used less and less, in my observation. As we cannot see the server-side script codes, it can be absolutely anything. Some parameters.
—SA