Related Clues:

• Letters in a letter
• SASE, e.g.
• Dict. shelfmate
• Something in an env.
• Abbr. on a business letter
• Ltr. insert
• Stamped return env., e.g.
• Env. abbreviation
• Collier's, for one: Abbr.
• In an env.
• Bus. letter extra
• SASE, perhaps
• Business letter abbreviation
• Envelope contents: Abbr.
• Env. insertion