Doctor Able Baker, BD (Hons), Fdl, Kp, Pdf(Escrow) Director of Blit Studies, Brazeneck College.
Professor Able Baker of Brazeneck College is a wizard with a seemingly impressive list of credentials but about which very little else is known. Pratchett uses his titles as a foil for poking fun at the tendency among acedemics to include a long list of honours after their names. He takes his name, Able Baker, from the first two words in one of the World War II phonetic alphabets, which continued Charlie, Dog, Easy, Fox. This has now been replaced by the International phonetic alphabet of Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, etc). But perhaps Wizards being conservative, explains the use of the traditional form. Able and Baker were also the names of the two atomic-bomb tests conducted at Bikini Atoll in 1946.
The various degrees following his names generally have connections to computers so, given this consistency and Pratchett's use of computer jargon in other references, this is Pratchett's likely reference for most of the degrees. In some cases he is simply poking fun at the whole credential idea in a more general way. Amongst the computer terms he sneaks two legitimate degrees in; BLit is Bachelor of Literature and BD is Bachelor of Divinity, although it is also a baud, a single information uni in computing.
FDL - stands for File definition language. In GNU-programming, an FDL is also the Free Documentation Licence, allowing the holder to use other peoples' intellectual property for free.
KP - in Great Britain is a make of snack nuts, as well as Kitchen patrol in the army, but a .kp file is also called a "knowbot" or "rapidshare", and is used as a worm virus which, without your knowledge or consent, will rapidly share the contents of your hard-drive with others.
Pdf is a file format.
Escrow is small town in between Lancre and Überwald not known to have a centre for conferring higher education degrees. In Roundworld law it is a 'limbo' status for monies or property held on behalf of another, in anticipation of conveyance; in a normal US home loan closing, the first year's property taxes and insurance premiums are placed in an escrow account from which the required payments are made.