By RPRA rules it is the ring and not the pigeon which is deemed to be raced. if the double rung pigeon has the appropriate ring covered or taped up, only showing the ring to which races is entered then this is accepted under RPRA RULES.
Call THE RPRA and you will find that it is a lupehole in their rules which can be exploited and used to the benefit of who wants to use them.
oh happy double rung days !!!