Related Clues:

• "Invasion" network
• Early run?
• Poker pot paper, perhaps
• Promise of repayment
• Indebtedness initials
• Gambler's debt, so to speak
• Telephonic trio
• Alphabet starter
• Letters on a note
• Promise of a sort
• Where you'll get ''Lost''
• Block letters?
• Letters on a chit
• CBS rival
• 'Dynasty' airer