It depends on whether the abbreviation is an acronym or an initialism. As "fubar" and "scuba" are usually pronounced as a word (making them acronyms), it would make sense to say "a fubar" and "a scuba diver". "FAQ" is a bit harder, because I have heard people say it like an initialism: "‹f›‹a›‹q›", while others pronounce it as an acronym /fæk/. Therefore, one should write either "a FAQ" or "an FAQ" depending on how that person pronounces it, ie, whether it is an acronym or an initialism.

It depends on whether the abbreviation is an acronym or an initialism.

• As "fubar" and "scuba" are usually pronounced as a word (making them acronyms), it would make sense to say "a fubar" and "a scuba diver".
• "FAQ" is a bit harder, because I have heard people say it like an initialism: "‹f›‹a›‹q›", while others pronounce it as an acronym /fæk/.
  Therefore, one should write either "a FAQ" (/fæk/) or "an FAQ" (‹f›‹a›‹q›) depending on how that person pronounces it, ie, whether it is an acronym or an initialism.

For me, it really depends on how the acronym is usually pronounced. As "fubar" and "scuba" are usually pronounced as a word, it would make sense to say "a fubar" and "a scuba diver". "FAQ" is a bit harder, because I have heard people say "‹f›‹a›‹q›", while others pronounce it /fæk/. Therefore, one should write either "a FAQ" or "an FAQ" depending on how that person pronounces it.

It depends on whether the abbreviation is an acronym or an initialism. As "fubar" and "scuba" are usually pronounced as a word (making them acronyms), it would make sense to say "a fubar" and "a scuba diver". "FAQ" is a bit harder, because I have heard people say it like an initialism: "‹f›‹a›‹q›", while others pronounce it as an acronym /fæk/. Therefore, one should write either "a FAQ" or "an FAQ" depending on how that person pronounces it, ie, whether it is an acronym or an initialism.