Vacuum is such a strange word to spell out loud. Just image this;
Person 1: I have this old vacuum cleaner here I want to sell, but I can't remember how to spell vacuum. Could you help me?
Person 2: Yeah sure, its 'Vee Ay See Double Yu Em.
Person 1: Thanks, hows this?
SECOND HAND VACWM FOR SALE
you get what I mean . . .