RSVP Convenience is a term used to describe the process of responding to an invitation. It stands for Repondez s'il vous plaît, which is French for 'please reply.' The acronym SAE, which is found in the crossword solution, stands for 'self-addressed envelope, ' which is an envelope that has been pre-addressed to the sender. This allows the recipient to easily respond to the invitation by simply placing their response in the envelope and sending it back.