[JLange]

I prefer the term “First Card.” To me this says what I need to know - that this is the first known card of a player. You could also add further qualifiers like First MLB Card to distinguish from minor league issues, or First Card with XYZ Team, or First Solo Card to differentiate from multiplayer cards, etc. Everything else that comes after that are not the first card. They may be key or mainstream or more desirable, but they are not the first. Even with my preference for a term like “First Card,” I am not opposed to clarifying or re-defining what is meant by “Rookie Card,” as right now it’s not an overly helpful hobby term.