Prevent silly tier heights being accidentally entered.
Prevent silly tier heights being accidentally entered.

jeffhsu3/dalliance,ENCODE-DCC/dalliance,dasmoth/dalliance,bartcharbon/dalliance,Traksewt/dalliance,warelab/dalliance,dasmoth/dalliance,Traksewt/dalliance,limeng12/dalliance,warelab/dalliance,jeffhsu3/dalliance,bartcharbon/dalliance,limeng12/dalliance,ENCODE-DCC/dalliance