This paper exanfines certain aspects of phonological structure from the viewpoint of ahstract data types, Our imnlediate goal is to find a format for l)honological representation which will be reasonably f,'fithful to the concerns of theoreti: cal phonology while I)eing rigorous enough to a(Irail a computational interl)retation. The longer term goal is to incorporate such representations into all appropriate general framework for llatnral language processing, i