Bayer

Designation = Letter[Number] Constellation
Letter = greek letter, [A - Q], [a - z] excluding j & v
Constellation = full name, abbreviation

Flamsteed

Designation = Number Constellation

Variable star

Designation = Bayer, [R-Z, Letter1Letter2, VCounter] Constellation
Letter1 = [A - Z] excluding J
Letter2 = [Letter1 - Z] excluding J
VCounter = V[335 - ...]