Related Clues:
- Letter abbreviation
- Business-envelope abbr.
- Env. abbr.
- Env. alert
- Abbr. spotted in the mailroom
- Cover sheet abbr.
- Envelope or memo abbr., perhaps
- Mailroom abbr.
- Abbr. often before a name
- Ltr.-routing word
- Incidentally, in chat room shorthand
- Business-envelope abbreviation
- Ltr. directive
- Abbr. before a colon
- "Incidentally," in Internet lingo