Bowell
Noted in the book Hogfather, page 181, concerning the location of the building feature known as Archchancellor Bowell's Remembrance.
This is described as a small circular hall, vestibule, with an outer door with a hatch and has a raftered ceiling.
This poses a question: where in the Unseen University Cut-Out Book is that hall? The implication is that as with features from later books that have had to be manually added to The Streets of Ankh-Morpork such as the Lady Sybil Free Hospital, this was conceived later than the design of the cut-out-and-assemble Unseen University.
Hogfather was published in 1997; the Cut-Out University (no code) was published in 2006. But we are told this is directly based on a far earlier creation, the original Clarecraft pottery model of the University whose cost and hernia-inducing qualities mandated a cheap, cheerful, and above all light-weight version. Bernard Pearson's version is not listed or priced on the website: but parallel constructions, such as the Guild of Assassins, were retailing at over £400 before selling out and also date from the late 1980's and early 1990's. So it is safe to assume Archchancellor Bowell's Remembrance was hiding in a potential niche of hyperspace when Bernard surveyed the university for the original model, and only chose to emerge in real time in 2006 with the publication of Hogfather. Just as the Mappe (pub. 1993) represents a city where, up until the publication of Night Watch in 2002, the Lady Sybil Free Hospital existed only in potentio.