Related Clues:

• Not yet filled, on a sched
• Not yet known, on a TV schedule
• Letters for a gap in the schedule
• Abbr. on a schedule
• Letters denoting "date not set"
• Unknown, on a sched
• Cast-list abbr
• 'I dunno,' in day books
• "I dunno," in day books
• Unfilled, on a sched
• TV Guide abbr
• Not yet on the sked
• Pending letters
• Sched. uncertainty
• Awaiting scheduling, in brief