Re: Note to my fellow Yanks ...
"Why they don't use the more descriptive "PA" that the rest of the world uses"
It's the same all over the world, certain brand names become so successful the brand become synonymous with the product type, even if it's actually another brand. Durex in Australia, Scotch Tape in the US, Sellotape in the UK, all the same product (and can cause confusion for Aussies in the UK and vice versa when asking for Durex in the wrong shop for he wrong reasons!)