[artdutra04]

I would vote for using the Nationals tag for older pictures when the event was called Nationals (prior to 2002, inclusive) and a Championship tag for all the pictures taken when it was called the Championships (2003 to present).

It just seems kind of weird to change the name of an event in the past because the name is different now. It's like having a regional called the [Some Company A] Regional for one year, and then called the [Different Company B] Regional the next year; all while demanding that you must refer to the regional as the Company B Regional and treat it as it it was always called the Company B Regional.