Our Electronic Field Guide has data in which we organize a number of sub-specific instances placing them in the hierarchy below the species, but these are not sub-specific in the sense of, say, plant varieties. Rather they are mainly sex and life-stage. I suppose calling these a taxonomic rank would not please taxonomists, but I wonder if there is any common terminology that encompasses both these and conventional taxonomic ranks, with which we could conveniently tag XML externally and object names internally.

Bob Morris