[feynmanistheman]

The Brits seem to do it for acronyms you pronounce, i.e. Fifa or Aids, but not the ones you spell out like HIV.

[chriswarbo]

> acronyms you pronounce

> the ones you spell out

If you're looking to distinguish these, you can use the term "initialism" for the latter.

http://en.wikipedia.org/wiki/Acronym#Nomenclature

[feynmanistheman]

Ah! Thanks, I knew there was a word for it.