Related Clues:

• Not backward, abbr
• Ahead, abbr
• Abbr. that may be followed by 'Re:' in a subject line
• Send on, as an email: Abbr
• Repeated string in a chain letter subject line
• Email subject-line letters
• Subject line abbreviation
• Abbr. on some Outlook messages
• Abbr. in an email subject line
• Start of some subj. lines