Waddiwassi 0 Newbie Poster

I'm currently working on a project that makes use of the FIX protocol and my role in my group is to work on decoding information that would be sent in the data stream but, after reading many of the specification docs on fixprotocol.org, I am still at a loss as to how this protocol does this. If anyone could give me a description of how it does the decoding of the data it would be much appreciated. Also I'd prefer psuedo code over actual code if possible. Thanks