Commonplace Book
What is a commonplace book? Here’s Wikipedia on the subject.
Commonplace books … emerged in the 15th century with the availability of cheap paper for writing, mainly in England. They were a way to compile knowledge, usually by writing information into books. They were essentially scrapbooks filled with items of every kind: medical recipes, quotes, letters, poems, tables of weights and measures, proverbs, prayers, legal formulas. Commonplaces were used by readers, writers, students, and humanists as an aid for remembering useful concepts or facts they had learned. Each commonplace book was unique to its creator’s particular interests.
“Commonplace” is a translation of the Latin term locus communis which means “a theme or argument of general application,” such as a statement of proverbial wisdom. In this original sense, commonplace books were collections of such sayings, such as Milton’s commonplace book.