Peritext

A broader term for “marginalia”, encompassing all sorts of elements which might appear alongside or surrounding a primary column of text.

Interesting examples

• Knuth’s books, of course
• Talmudic analysis
• Concrete Mathematics (2nd ed) by Graham, Knuth, and Patashnik includes “graffiti” from past students of the book (and TAs, and quotes from famous mathematicians). Mostly they’re funny comments, but sometimes they’re earnestly helpful. (via Ari Bader-Natal)

• Sort of: Charles Gute - Revisions and Queries

Related

• Few digital reading environments support marginal notes