Actually, I've heard more people refer to MREs than c-rations. After the relief effort fiasco in Ethiopia and Somalia several years ago involving MREs, plus a couple jokes during Johnny Carson's and later Jay Leno's monologues, I think a great many Americans know what MREs are. I think very few people know what c-rations are just as very few nowadays even know about eight-track tapes, Beta video recorders or LPs.