What do the letters in London Bus routes mean?

Some may refer to the initial of the area they're based, but the ones I know refer to some particular feature or theme of that bus or it's route.

For example, the RV in RV1 stands for River, because it sort of follows the Thames (it's intended as a tourist route to get people from Tower Bridge to Covent Garden via London Bridge, the South Bank, Waterloo and the London Eye).

H on the other hand refers to buses that are 'Hail and Ride'. These are small buses that start and finish at specific stops, but then weave around tight residential routes where there are no specified stops, and people flag them down (ie hail them) where required.

P4 Bus Route

The letter signifies where the bus travel to/from or through

P = Peckham

K= Kingston

RV= River ( or something like that)

C= Central London

U= Uxbridge

E.g. P13 Streatham - Peckham - New Cross Gate

Apart from 'N', I believe the letters stand for the area in which that particular route is located (for example, P for Peckham). I know the 'C' stands for 'Central', as in Central London, but I'm not sure about the other letters. I guess the areas in which you saw them would be a clue :0)

There is no accurate timetable for London buses, most times are estimates due to the vagaries of traffic congestion.

The ones I know are -

E - Ealing

H - both Harrow and Hounslow

U - Uxbridge