A Correction, in Nicholas Upton, Treatise on Military Arts and Heraldry
Medium: Ink and pigments on vellum
Bound into a volume containing manuscripts owned by the 16th-century collector, Robert Cotton, this is a page of a treatise on military arts, arms and heraldry by Nicolas Upton, a canon at Salisbury (became precentor 1446) and Wells cathedrals and the foremost English authority on heraldry in his day. It is uncertain where the manuscript was made.
Top left of the page, two small crosses with dots in the angles of their arms indicate a correction. The lines of writing after the cross in the upper margin are meant to be inserted at the point where the second cross was written at the end of the first line. Medieval scribes developed symbols to indicate all types of corrections out of necessity. Hand copying meant mistakes were common.