Are you one of those people who got so used to the Q being on 6th Avenue in the 80s and 90s, you forgot it was really a Broadway line "temporarily" rerouted onto 6th Avenue? Remember July of last year? People were thinking the Q was being rerouted off its normal route. Yeah, it does seem sort of strange at first to have it on Broadway but not it seems normal.
6th Avenue-B, D, F
Broadway-N, Q, R, W
The V didn't exist in July. Note that with the exception of the W, the Broadway Line uses all available letters between N and R. O and P can't be used for reasons previously discussed here. The B, D, and F naming comes from the old IND designations which are no longer followed since the B/C flip-flop in 1998.