Good luck, Sandy, and to your friend!
Did it seem to be a popcorn or ornamental variety?
I wonder if there really IS any recognized corn cultivar named 'Ruby', and not just left-over seeds that the marketing department decided to move under a "sold-as" name.
Or some cultivar that the breeder never registered ... whatever the process is for getting an "official" cultivar name.
Say they had 'Ruby Queen' but they have to pay the vendor more if they sell it as 'Ruby Queen'. So they called it "Ruby".
Or they never paid for the right to multiply 'Ruby Queen', if that's a thing. Or the grower knew that it was somehow "off-spec" and couldn;t be sold under the name of the "real" 'Ruby Queen'.
All speculation.
I just know that Home Depot sold me some bulbs with a name slightly different from any recognized variety, but similar to a variety that looked very similar. I assume that name-fiddling somehow evaded some expense or law or license.
Our database doesn't list 'Ruby', just:
Sweet Corn (Se) (Zea mays subsp. mays 'Ruby Queen')
Popcorn (Zea mays subsp. mays 'Ruby Red')
Popcorn (Zea mays subsp. mays 'Robust Ruby Red')