Related Clues:
- Business letter abbreviation
- Envelope contents: Abbr.
- Env. insertion
- Bus. letter attachment
- Collier's work: Abbr.
- Ltr. accompanier
- Ref. set
- 5 Placed inside: abbr.
- Check inside?: Abbr.
- SASE, for example
- Placed inside a pkg., e.g.
- What's inside an env.
- Ltr. extra
- In this env.
- Something besides the ltr.