This plant has been sold for decades under the name Iris ensata variegata, which is obviously formatted as a scientific name. However, it isn't a recognized one. Nurseries commonly attach these pseudo-scientific names to plants that have what they consider to be note worthy traits (variegata for plants with variegated leaves, alba for plants with white flowers, etc). To make a long story short, this plant was eventually given a, more proper, cultivar name of 'Silverband' in 1989. Naturally, some nurseries continue to sell it as Iris ensata variegata, just to maintain plenty of confusion.
This sort of thing happens now and then.
Border Bearded Iris (Iris 'Minnesota Mixed-Up Kid') was in commerce for decades, under a variety of different names, before it was registered with AIS in 2003.
