Why go with more obscure codes, that doesn't fix the problem, it just shuffles the order of the confusing variables around for less techy people.
Go with something that makes sense..why r7 and r9? whats the r for? what does 7 relate to, or 9 for that fact? (People that are tech savvy can figure out what card is what pretty easy, but ask my wife which is better a R7 250, R9 290, and R9 290X and get a blank stare).
Why not codes like B,G and E (budget, gaming, and enthusiast or such)
THEN ask my wife 'which is more powerful, a B250 or a G290" after 5 seconds of telling her what B,G, and E stand for, even she could tell you which is better.