how to write up class name in 2.5

[RickyBlender]

what are the rules to write up class name and the bl_idnameÉ

like in

class INFO_MT_mesh_Gencurves1_add(bpy.types.Menu):

bl_idname = “INFO_MT_mesh_Gencurves1_add”

is this add necessary or not ect

thanks