These rules generally ensure that no overlapping will occur, although in the case of stations where large numbers of stations in adjacent markets are in close proximity to each other, it is possible that such overlap can occasionally happen (see, for example, the case of WJLP). Additionally, stations may broadcast some of their subchannels under major channel(s) in the 70–99 range, so long as multiple stations do not attempt to use the same major channel(s). These numbers are certain to be unused, as 69 was the highest assigned channel prior to the conversion to digital broadcasting. The document does not address the use of certain other major channel numbers: