Augustine On Lying is now in the Logic Museum. He discusses some subtle cases beyond those which I discussed here. For example (4.4) if lying is telling a falsehood with the purpose of deceiving, what if I purposely say something false to someone who I know will not believe me, but who believes I am serious? Conversely, there is the opposite case of a person who speaks the truth in order to deceive. Knowing he will not be believed, he speaks the truth on purpose because he knows or thinks that what he says will be reckoned false, merely because it is spoken by him.
He also mentions the case of joking, which are not lies “seeing they bear with them in the tone of voice, and in the very mood of the joker a most evident indication that he means no deceit”.