Complex sentence: OTC members are classed as Officer Cadets (OCdt) despite the majority not having passed officer selection, and are members of the Army Reserve, paid when on duty they are not classed as trained ranks and cannot be mobilised for active service.
Split into simpler sentences: OTC members are classed as Officer Cadets (OCdt) despite the majority not having passed officer selection, and are members of the Army Reserve, paid when on duty. UOTC Officer Cadets are not classed as trained ranks and cannot be mobilised for active service.