In fact the only one official cyling category in which the UCI alow to lie is handbiking. We come with a set of pictures of different handbikes. You can see that they are not same and even among handbikes there are several categories. It depends mostly from which part of backbone the racer is disabled. Some can move with the upper part of the body and can work more some cannot.
These pictures are a little bit older from 2003 WCH.