Possible Clues:

• Stickie notation
• 'This might be of interest ...,' for short
• Header on many a forwarded email
• Memo-heading initials
• "Here are the facts," briefly
• Forwarder's abbr
• Forwarded email header
• 'By the way' memo abbr
• "Just so you're aware..."
• 'Just a heads-up,' on a memo