(1) Initially an acronym for Best Of Fandom; several fanthologies bore the title with the appropriate year attached "Best of Fandom '57," "Best of Fandom '58," "Best of Fandom '63" &c. Several Corflus published BOFs for the year preceding the year when they were held.

(2) A second unrelated meaning has crept into accepted fannish usage in more recent times, the acronym instead standing for Boring Old Fart. These BOFs have become as organized as it is possible to be in an anarchistic meritocracy: See SBOF.