f17r

[-JKP-]

Another speculation:

l[iber] p[re]c[eptoru]m (Moses Maimonides?)

At least, it would not be contrary to what we can read. the letter which looks like a Greek ny or Latin v seems to be a Latin p, cf. 116v and the single letter, that looks a bit like Greek gamma on 66r, which could be a p as well

Helmut, I hadn't thought of reading the whole luc'm/lpc'm as an abbreviation, I was only looking at the last part of the word as an abbreviation, but you're right. It's possible it may have been written as highly abbreviated and "book of instructions" would fit as well as any of the other possibilities.