> Edo period (we could have tags for different historical periods) [YES. We have>a lot of entries with "Edo/Muromachi/Kamakura/etc. period" added and a "misc"
Also, the Ritsuryo period? That's not an official period though and it describes a time when a certain system of rule was in place. It's of course more relevant to name that than to say late Asuka / early Nara period.