Related Clues:

• Unknown, on a sched.
• Unfilled-time-slot letters
• Necessity: Abbr.
• Mandatory: Abbr.
• TV listing abbr.
• Listings abbr.
• As yet unscheduled, briefly
• ''More info later''
• ''We'll let you know,'' on a TV schedule
• ?, on a sched.
• [We'll tell you later]: Abbr.
• ''Unknown,'' on a sked
• Unscheduled, so far (Abbr.)
• 'More later,' on a sched.
• Not yet filled: Abbr.