Im playing ruby, and I want a bagon, but, I checked bulbapedia and it says I can find it on b1f 2r, what does 2r mean here ?
Because you never responded to my comment, I'll just assume you made a mistake. Please tell me if this assumption is wrong, and I'll convert this answer to a comment.
"F" stands for "floor".
"B" stands for "basement".
"R" stands for "room".
source: I have seen dozens of maps on Bulbapedia and none of them have used these abbreviations for different things. Apparently these abbreviations came from official guide books.