Possible Clues:

• Letters accompanying a tip
• "Here's an update," briefly
• “This might be of interest,” in a memo
• 'Just a heads-up . . .'
• "Just so you know ..." initials
• 'This might be good to know:'
• "Here's a tip ..." letters
• 'in case u didn't know . . .'
• “You should know” in text
• "Just so you know" letters