This weekend I had configured my DishPlayer to record the French Open on NBC. The recording started on schedule, but instead of the French Open there was a WNBA game on. When I switched to the OTA NBC (channel 4) the French Open was playing. I went back to the Dish and noticed that the channel identification was WDC-N for channel 750. The local call sign for NBC in Washington, DC is WRC. Is there a difference between WDC-N and WRC? I thought it would show the same programming all the time.