To the uninitiated, course codes are nothing but a number; by chance some may appear to be road numbers, but in reality they contain several pieces of information which a time triallist can understand.

The format of a course code can vary between districts, but follow one of several general patterns.
The first two methods share the same information ideas, but ordered differently. Districts like the East use the system of District Code followed by Distance followed by /Location. An example is the B10/3 – B tells us that the course is in the East District, 10 tells us that the distance is 10 miles, /3 indicates the specific location of the course on the A11 near Attleborough.
Next, other districts like our southern neighbours London East use the format District Code followed by Location followed by /Distance. An example here is the E2 series of courses (E2/10, E2/25, E2/50, E2/100) which are all based on the A11 east of Cambridge.

Some districts use a less conventional method of naming courses: South (P), North (L), Yorkshire (V), West (U), Teesside (M), Manchester (J) have various two, three and four number codes to follow the district code.

The East District also employs two other naming conventions. One is for non standard courses where BS precedes a location number – the BS19 is the early season Ely Hardriders circuit course (although one would still need a local tester, handbook, or this website to indicate exactly where it is, and that it is approximately 25 miles). The second is for hillclimbs, where BHC precedes a location number; BHC/1 being the hill of choice for the EDCA hillclimb championship.
However, the BHC/1 for a hillclimb is not anywhere near the B10/1 – they are in fact opposite sides of the district!