Bit 14 is set to 1 if drop frame numbering is in use; frame numbers 0 and 1 are skipped during the first second of every minute, except multiples of 10 minutes. This converts 30 frame/second time code to the 29.97 frame/second NTSC standard. Bit 15, the color framing bit, is set to 1 if the time code is synchronized to a (color) video signal.