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For example, I was watching Indiana Jones: The Last Crusade. The opening credits listed a bunch of actors, ending with "And Sean Connery as Professor Harry Jones". I remember watching Star Trek: The Next Generation and they would always do this for "Whoopi Goldberg as Guinan" or "Jean de Lancie as Q".
(Please note: This question is in reference to credits displayed in the opening sequence of an episode or film. This is not in reference to credits as they are displayed on IMDB).