Stet is a form of the Latin verb sto, stare, steti, statum, originally used by proofreaders and editors to instruct the typesetter or writer to disregard a change the editor or proofreader had previously marked. This usage of the verb, known as the "jussive subjunctive", derives from the active-voiced third-person subjunctive singular present and is typically translated as "Let it stand" or "As you were".
Conventionally, the content that included the edit to be disregarded was underlined using dashes or dots and stet written and circled above or beside it. Alternatively, a circled tick or checkmark could be placed beside the content in a margin.
Stet is sometimes also used imperatively, as in, for example, "Stet that colon", or, if left on a board that might otherwise be cleaned, "Do not erase".