Hi, Im not sure if I understand your question, are you looking for feature specs on IOS code or naming conventions meaning.
I'll throw two answers.
If looking for feature base on code and/or platform go here.
http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp
If looking for code naming conventions go here.
http://www.cisco.com/warp/public/620/1.html
HTH
Jorge
Jorge Rodriguez