Possible Clues:

• Back soldiers with the wild distinctive mark
• Bottom line contents, often
• US soldiers upheld Constitution — that’s distinctive
• Indication of key
• Is over Midge Ure's autograph!
• Identifying script
• (In music) the sharps or flats that follow the clef and indicate the key
• Ink on a contract
• Endorsement for Sicilian leaders' good temperament
• Tune that can make a singer's name