Possible Clues:

• Morgue ID
• ID on 'CSI,' maybe
• Digital identifier?
• Identifier seen in the "Six Feet Under" title sequence
• Item seen in the "Six Feet Under" title sequence
• Item seen in the 'Six Feet Under' title sequence
• ID checked by a coroner
• ID given to someone who's late?
• Final footwear?
• Morgue identification