Related Clues:
- Letter-routing letters
- Memo header, for short
- Envelope abbreviation
- Letters on many business letters
- Abbr. under an address
- Ltrs. in a letter
- Abbr. on a business envelope
- Bottom-of-env. header
- Modern chain letter: Abbr.
- Routing abbr.
- Abbr. before a name in a memo
- Abbr. before a name on a memo
- Line below a business name, perhaps
- Bus. letter directive
- Mail-routing abbr.