Lancelot-Graal Project
Amsterdam, Bibliotheca Philosophica Hermetica, MS 1, vol. ii, f. 202r

© Courtesy of the Bibliotheca Philosophica Hermetica

This blemish is a tear in the parchment that was present before the text was written since the writing avoids it.  Originally it was sewn up wiht thread, for which the pricking holes are visible on both sides of the tear.  Repairs of this sort based on sewing were a very common way of ensuring that a tear in the parchment would not spread and further damage the page: such defects were not considered sufficiently serious to warrant discarding the leaf.