Issues with Branch Naming (BB-6095)

I've got a branch called "A#1_A", and when i try to compare to main branch i get: "spec must contain '..'".

Not sure if the "_" or the "#" is the issue.

I've noticed this issue with using dashes "-" too, e.g "A#1-A".

Can you confirm what the required conventions are for naming branches? Should probably be documented somewhere too...