5.011: What's the font used on their merchandise, adverts, etc?
We're not entirely certain, but we think it is a version of Compacta Bold or similar. Jamm!n has a .zip file of 5 members of this font family (in TrueType) on Mancentral.
(http://jumper.mcc.ac.uk/~ttl/KLF/Misc/compacta.zip)
However, whilst many of the letters of the KLF font match with these, some don't. It has also been suggested that the KLF font may be related to Folio, Helvetica, or even Hattenschweiler.
To be honest, we're not sure. If you really want to know, try to contact either Mick Houghton (who did their publicity) or Scott Piering, or even Bill or Jimmy themselves. (See 1.010 for addresses).