When Did RC Become Most Important?

[BioCRN]

The RC designation has no basis in reality for pre-war and should be ignored.

One could draw so many lines here that it is true because people buy into different definitions/exclusions for their own collections.

Even though card sizes were not standardized, some people don't count post cards/exhibit/oversized cards as "real" cards or RCs.

Some people won't count regional-only issues.

Some people won't count small checklist issues regardless of distribution area because of the lack of representation of teams on whole.

Some people won't count cards that come from "WG" game sets...or mail-in redemption sets...etc.

Then we have the ambiguity of the actual years of some issues because it's believed to be a multi-year issue. A card may have been distributed in 1910-1911 even though it's considered part of a 1909 set.

There's gotta be even more than this. I consider most all of it valid given the lack of a cohesive hobby opinion and I don't really care if this opinion solidifies into a consensus.