Numbers of texts' divisions are given at the margin (κεφαλαια, Ammonian Sections, Eusebian Canons).
The marginalia were edited by J. Gwenogvryn Evans with John Rhys in their 1893 edition of the Book of Llandaff.
In 1948 Tolkien was visiting his publishers, George Allen & Unwin, to discuss some disappointing artwork that they had commissioned for his novella Farmer Giles of Ham, when he spotted, lying on a desk, some witty reinterpretations of medieval marginalia from the Luttrell Psalter that greatly appealed to him.