The Kokka Taikan (国歌大観) is a compilation encyclopedia of Japanese waka poetry early and modern, also serving as the de facto academic indexing system for poetry about which little is known. It is published by Kadokawa Gakugei Shuppan.
In academic literature or literary criticism, the Kokka taikan reference number is more likely to be provided for poems by unknown or anonymous authors or when the year or location is unknown. For example, where records of poetry competitions in notable households are harvested, only a period and the location may be known; these poems may be valuable if referenced by masterpieces from the same or rival literary group.