It's not a bug, it's a feature.

It's always fun to take a look at a newly acquired manuscript item and find an interesting feature.

In the case of the leaf pictured today, I was delighted to find that a tiny hole in the parchment had not only been avoided by the scribe (as usual), but attended to by the rubricator, who circled it on one side of the leaf (see the first image, between the words "i[n]ter" and "ones"), and even sort of included it in a bit of rubricated decoration on the other side.

When the vellum had a natural flaw, I guess it was reasonable to call attention to it sometimes, rather than just ignoring it. If your vellum is freaky, then own it, I guess.