Instead, the C-Ration, still designated as a packaged ration intended for infrequent or short-term use, went through a series of largely unsuccessful minor revisions. This decision resulted in limiting troops in the field to a single class of packaged ration that despite meal variances, was neither suited to varied field environments nor for long-term use. Troops continued to complain of the monotony of a single class of field ration with one or more unpalatable menu items, especially where A and B rations were not available for extended periods. Primarily implemented due to cost concerns, the selection of a heavy canned wet ration resulted in a severe weight penalty for troops marching on foot and forced to carry a multi-day supply of rations. The overuse of the canned wet ration reached an extreme during the Vietnam War, where American troops resorted to placing stacked ration cans in socks to save bulk and reduce noise on patrol, while their enemy increased their mobility by carrying lightweight rations of dry rice. The Quartermaster Branch's insistence on canned wet rations for all postwar field issue, and the failure to develop a suitable lightweight dehydrated or other dry ration for jungle and other extreme environments led directly to the hurried development of the LRP ration or Long Range Patrol ration in 1966. Starting in 1958, C-Rations were slowly replaced by the nearly identical canned Meal, Combat, Individual ration. These rations were issued for most of the next two plus decades, until they were replaced by Meal Ready to Eat or MREs in the early 1980s. The C-Rations during the Korean War led later to the introduction of instant coffee to South Korea.