I didn't want to revive an old thread, so thought I'd post a new one. In a thread about Group B, forum member FAL posted this:

Quote Originally Posted by FAL
GpB was never originally intended to be a rally catgory, only a racing category. The new Appendix J for 1982 (GpN and A) was introduced to ban the many, largely British Gp1/2/4 "homologation specials". Without an extension of Gp2 and Gp4 for 2 years and GpB, there would not have been enough entries on International rallies in 1982 and 1983.
I'd be very interested in hearing more about this. What were these 'homologation specials', and why were they a matter of concern?