What’s the meaning/significance/origin of using the word "classic,"in the names of tournaments?
They’re sponsored by companies that style themselves “Ltd.” 
Sorry. Don’t get it.
Maybe this should be in GQ. Surely someone knows the reason for this naming convention? I put it in IMHO because I thought it would be an opinion thing.
I don’t think it has any meaning and I am not sure it ever did; it’s just a glam word they throw in to show it’s a high-class event, not some sweaty jockfest. Which is much the same position of “Ltd.” or “Limited” outside of those countries where that’s a valid company descriptor. In the US, it’s just snootiness.
“Classic” may have roots in the sense of “conforming to the [old school] rule book” and excluding competition forms from later and lesser sources. But I will bet it’s nearly meaningless except in my first guess sense of “bring your own wine glass.”
I follow golf closely and I’m not sure there is a meaning. They aren’t opens where amateurs are invited, and they aren’t invitationals where the field is hand-picked. I think it’s just a name as far as I can tell.
Meaningless, eh? Interesting.
Well, meaningless is a subjective term. Calling a tournament a classic defines it in a certain way, just as “annual” or “traditional” or “summer” or “exclusive” or even “championship” does, without necessarily meaning very much in and of that term.
Classic == “classy and kinda upscale, y’know?” is how I interpret it.
In other words, similar to the MLB’s use of the word “world” in “world series.” 
I thought that was because a newspaper called ‘the World’ was an early sponsor.
Urban legend, promulgated by a historical writer I admire greatly.
World meant world, as absurd as its application here is.