Related Clues:
- Directive on an env.
- Letters on some letters
- Ltr. letters
- Ltr. recipient pinpointer
- Doc. with a ltr.
- Env. routing indicator
- Abbr. before a name on an envelope
- Letters directing letters
- Envelope letters
- Cover-letter letters
- Something inside an envelope: Abbr.
- Abbr. indicating to whom it may concern
- Ltr.-routing aid
- Letters that help a letter sorter
- To on a fax