Related Clues:

• Memo intro, sometimes
• About, on a memo
• Memo line
• On the subject of
• Memo subject header
• As to, in memos
• Legalese words
• Memo leadoff
• Memo-starting phrase
• About, in legalspeak
• Concerning, on a memo
• Legal memo words
• Topic preceder
• Apropos of, in contracts
• 48-Across starter