Two varieties are permissible, both having close - fitting, dense, weather resistant double coats with the top coat either straight or wavy and coarser in texture than the undercoat which is soft, short and dense. (akc.org)
The weather resistant double coat consists of a long, flat, thick, outer coat of coarse hair, straight or slightly undulating, and lying over a dense, fine, woolly undercoat. (akc.org)
This breed has a weather resistant double coat that is straight and short and held closely to the body. (caninejournal.com)