NATO reporting names use common starting letters for different categories of weapons. For surface-to-surface missiles all begin with the letter S. Most of the names chosen wouldn't raise eyebrows: Sapwood, Sasin, Sibling, Stone... Some of them seem to have an appreciative "cool factor": Skyfall, Saber, Stiletto... But generally there isn't a derogatory theme to these code names. For instance, codenames for fighter jets include Foxhound, Firebird, Fencer, and Felon. Some of these are really cool names that could have been given to western jets by marketting while others seem derogatory. There's not much of a pattern here.