"Flagship" properties - how are they defined?
 

Seeing the recent Biography Channel show about Mr. J.W. Marriott had me wondering what Marriott as a corporation considers its worldwide "flagship" properties, by brand, region, or both?

I've heard this term defined several ways, e.g. JW Marriott as a flagship brand, RI as a flagship extended-stay hotel, or Marriott Marquis as the flagship hotel in NYC.

Is there a definitive list that Marriott keeps, or is term mainly subjective?