Chainring compatibility
Unfortunately chainring compatibility can be a bit more complicated than number of bolts, BCD and pattern.

Higher end cranks such as Shimano Dura Ace or Ultegra have rings that are shaped to blend into the crank body. Those cranks are only compatible with the rings specifically made for them. 

Some cranks may also require rings where the mounting points are offset laterally from the plane of the circle of teeth.