Related Clues:
- Compton's, for one: Abbr.
- SASE, often
- Mailers shorthand
- Letters on business letters
- Letter routing abbr.
- Letter-bottom abbr.
- An SASE is one
- Env. in an env., say
- Env. insert
- Letter-routing abbr.
- Envelope shortening
- Letter-bottom letters
- Letter-routing letters
- Memo header, for short
- Envelope abbreviation