Period genre?

There are number of period/historical films listed on the database.

For history, the rules are strict that it should be a film about real events.

But since there are a number of films which have a period setting, why don't we have the "period" genre in the list as well?

A lot of period films have been wrongly listed in the historical genre due to this. For example, The Last Samurai is not a historical film. It's a period action drama but since there's no "period" option, it has been listed as a history film. 

Plus, when we can have "music" and "musical" which look similar but are different, why can't we have "history" and "period" both? This would even prevent confusions in the future.

All in all, just a suggestion :)