Readers have been leaving grumpy notes in books for as long as there have been margins to leave them in.
A partial, embarrassing inventory of the systems I've adopted and abandoned, and what finally worked instead.
A pressed leaf, a receipt used as a bookmark, somebody else's marginal notes — the accidental archive inside a used book.
Underline, marginal note, and dog-ear each record a different kind of reaction — and I keep forgetting that.
Before 'commonplace' meant ordinary, it named a specific kind of notebook — and a specific kind of reading.
Not just underlining. The word covers a much wider habit than the pencil marks most people picture.