JAR FCL1.310 Subpart H
All instructors shall hold at least the licence, rating and qualifications for which instruction is being given (unless specified otherwise) and shall be entitled to act as pilot in command of the aircraft during such training.
So to teach on a SEP for any of the specified differences:
Retractable U/C
Superchargers/Turbochargers
VP Prop
Presurisation
Tailwheel
then you must have been signed up for that difference, unless you flew aeroplanes with that difference prior to 1 July 1999 (granfather rights).