Hi, Mr Pedant here
Most of these are not actually acronyms (IMHO), they are initialisms.
Acronyms are initialisms that can be pronounced and usually create new words. For example:
RADAR =
Radio
Aid for
Detection
And
Ranging
SCUBA =
Self
Contained
Underwater
Breathing
Apparatus
NATO =
North
Atlantic
Treaty
Organisation
Initialisms are the ones that can't be pronounced. For example:
IBM
TDi
There is a grey area, however, with initialisms that can, sort of, be pronounced. For example:
JPEG
VTEC
These are sometimes called
acronym–initialism hybrids 
Discuss
