Commonplace markers, which were used from the sixteenth to the eighteenth centuries, are punctuation marks that indicate a passage is worth copying
As their name implies, commonplace markers point out commonplaces (sometimes called sententiae): words of wisdom or well-phrased ideas. These maxims are generally short enough to be easily memorized or quickly jotted into a personal miscellany or commonplace book. → A commonplace book is a collection of memorable quotes that have a general quality, a profound conclusion on life. To me, they seem like an indication of what an author, editor or reader thinks should be taken away from a passage or manuscript. Like a central message.
In medieval manuscripts, commonplaces were often highlighted by leaving a space at the end of the commonplace or sometimes indicated with different punctuation marks.
Eventually, however, double inverted commas came to indicate that a text was “theirs” (quotations belonging to an author) rather than “ours” (commonplaces for a collective readership). → Commomplace = we have the same fundament beneath our lives