The codes and their meanings are as follows:

01 – eyesight correction
02 – hearing/communication aid
10 – modified transmission
15 – modified clutch
20 – modified braking systems
25 – modified accelerator systems
30 – combined braking and accelerator systems
35 – modified control layouts
40 – modified steering
42 – modified rear-view mirror(s)
43 – modified driving seats
44 – modifications to motorbikes
44 (1) – single operated brake
44 (2) – (adjusted) hand operated brake (front wheel)
44 (3) – (adjusted) foot operated brake (back wheel)
44 (4) – (adjusted) accelerator handle
44 (5) – (adjusted) manual transmission and manual clutch
44 (6) – (adjusted) rear-view mirror(s)
44 (7) – (adjusted) commands (direction indicators, braking light, etc)
44 (8) – seat height allowing the driver, in sitting position, to have 2 feet on the road at the same time
45 – motorbikes only with sidecar
70 – exchange of licence
71 – duplicate of licence
78 – restricted to vehicles with automatic transmission
79 – restricted to vehicles in conformity with the specifications stated in brackets on your licence
101 – not for hire or reward (that is, not to make a profit)
102 – drawbar trailers only
103 – subject to certificate of competence
105 – vehicle not more than 5.5 metres long
106 – restricted to vehicles with automatic transmissions
107 – not more than 8,250 kilograms
108 – subject to minimum age requirements
110 – limited to transporting persons with restricted mobility
111 – limited to 16 passenger seats
113 – limited to 16 passenger seats except for automatics
114 – with any special controls required for safe driving
115 – organ donor
118 – start date is for earliest entitlement
119 – weight limit for vehicle does not apply
121 – restricted to conditions specified in the Secretary of State’s notice
122 – valid on successful completion: Basic Moped Training Course
125 – Tricycles only