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Historically, wire center boundaries have been used in drawing area code boundaries, even if that meant splitting a rate center between two area codes.For instance, in the 1997 split of area code 415 in California, the "San Francisco 3" rate center (covering the southern part of San Francisco and portions of some adjacent suburbs) was split between 415 and 650. In the days before competition, this would have been a reasonable solution, keeping as much of the city as possible in 415, while moving as much of the suburban area as possible into the new area code. Under present-day conditions, with local competition but with LNP in its infancy, a split that divides a rate center actually aggravates the problem of prefix exhaustion, because each competing carrier now needs a prefix in each area code of a rate center, in order to serve customers on both sides of the area code line. Even once LNP is fully implemented, it will still be a bad idea to split a rate center between area codes, because it will require effectively creating two rate centers.