76.1601—Deletion or repositioning of broadcast signals.
Effective April 2, 1993, a cable operator shall provide written notice to any broadcast television station at least 30 days prior to either deleting from carriage or repositioning that station. Such notification shall also be provided to subscribers of the cable system.
Code of Federal Regulations
Note 1 to § 76.1601
:
No deletion or repositioning of a local commercial television station shall occur during a period in which major television ratings services measure the size of audiences of local television stations. For this purpose, such periods are the four national four-week ratings periods—generally including February, May, July and November—commonly known as audience sweeps.