The bowie knife is an iconic knife design, popularised in part by its extensive use in the Vietnam war. The bowie blade shape is a distinctive one, the blade mostly straight until the point where the spine meets the blade edge through a concave relief. This relief is known to hold a swedge and is sharpened on some examples. The spine on a bowie knife is usually plain, with a swedge from its midpoint to the tip of the blade. However, as popularised by the Rambo franchise, serrated and toothed spine bowie knives are also available. The Washington-based knife company: SOG began their business with a recreation of the Special Operations Group bowie knife that featured a double-ridged spine.