The Entry Forms show:-

RACE 5 : (A) LIGHTWEIGHT & (B) ULTRA-LIGHTWEIGHT

No mention of a SuperTwin Race in the Entry Form

Race 1a - Newcomers
Race 1b - Post Classic
Race 2a - Junior Classic
Race 2b - Lightweight Classic
Race 3 - Junior
Race 4 - Senior Classic
Race 5a - Lightweight
Race 5b - Ultra-Lightweight
Race 6 - Senior


However in the Regs:-

1315 Race 5 The SUPER TWIN/LIGHTWEIGHT MANX GRAND PRIX RACE (4 laps) in 2 capacity classes run concurrently


Class A - SuperTwin
201cc – 350cc 2 stroke 2 cylinder
Up to 650cc 4 stroke 2 cylinder

Class B - Lightweight
Up to 125 cc 2 stroke single cylinder, 6 gears maximum
251cc – 400cc 4 stroke 4 cylinder. Rebores up to Manufacturer’s maximum rebore sizes are permitted Up to 450cc 4 stroke single cylinder


It all sounds strange to me !!!!!