Wiktionary
n. 1 (context computing English) beginning of file. 2 (context Internet English) big old frown. 3 birds of a feather (group of people with common interests from the phrase "Birds of a feather flock together"). 4 best of friends.
Wikipedia
BoF or BOF is an abbreviation for:
Usage examples of "bof".
After that we had tarried there a few dayes at the cost and charges of the whole Village, and had gotten much mony by our divination and prognostication of things to come: The priests of the goddesse Siria invented a new meanes to picke mens purses, for they had certaine lotts, whereon were written : Coniuncti terram proscindunt boves ut in futurum loeta germinent sata That is to say : The Oxen tied and yoked together, doe till the ground to the intent it may bring forth his increase : and by these kind of lottes they deceive many of the simple sort, for if one had demanded whether he should have a good wife or no, they would say that his lot did testifie the same, that he should.
Voluntati sacrarum intendo scripturarum, vos dissonantiam facitis, verendumque est ne aratrum sanctae ecclesiae, quod in Anglia duo boves validi et pari fortitudine, ad bonum certantes, id est, rex et archiepiscopus, debeant trahere, nunc ove vetula cum tauro indomito jugata, distorqueatur a recto.