Would you say An FAQ or A FAQ? Not to be mean, just not sure---cause pronounced it sounds like 'an' but spelled looks like 'a'
Since FAQ is an acronym, the "F" here does not sound like your average "F". Phonetically it could be represented as "EFF".
While "an FAQ" looks strange, it is grammatically accurate.
The beeb (BBC) works in a similar way. Things that are spelled out are put in all caps ("ACC") and things that are pronounced are put with only a leading capital ("Nato").
Of course, that's just the journalism wonk in me speaking.
We just need all high school teachers to find time between teaching basic literacy to teach kids one style guide for these sorts of things.