Related Clues:
- Freelance writer's encl.
- RSVP encl.
- Postpaid enclosure: Abbr.
- Letter-bottom letters
- A MS. might come back in it
- Auto engineering org.
- It's used to return mail: abbr.
- International Reply Coupon rel.
- Aid in answering: Abbr.
- Mail courtesy, briefly
- It facilitates replying to a MS.
- RSVP facilitator
- Major coll. fraternity
- Manuscript enclosure (Abbr.)
- Motor oil abbr.