The Thatcham list shows all the categorys for each Thatcham approved system.
Thatcham Cat 1
Alarms & Immobiliser
Unit must feature protection for the doors, boot and interior.
Dual immobilisation
All black wiring
Battery back up siren
Anti Scan and Anti Grab rolling key code
Thatcham Cat 2
Immobiliser
Dual immobilisation
All black wiring
Anti Scan and Ati Grab rolling code remote or touch key