Which term is used for a mark that indicates where something should be inserted in a text?

The term "caret" is used to refer to a mark indicating where something should be inserted in a text. It is typically represented by a small upright arrow (^) and signifies a position for additional text or a correction to be made. This symbol assists writers and editors in indicating areas that need attention without altering the original content directly.

The other terms listed do not pertain to text editing or marking. "Denouement" refers to the resolution or conclusion of a narrative plot, particularly in literature. "Cavil" means to raise trivial objections or complaints, which is unrelated to textual insertion. "Calumny" denotes a false accusation meant to damage someone's reputation, which again does not connect to the concept of marking a position in text. Therefore, the correct choice aligns with the specific function of indicating insertion points in written material.