During the late 1980s and early 1990s, the Korean Young Chang company manufactured Squier electric guitars and basses for Fender Musical Instruments Corporation. The "E" serial number prefix on Korean Squiers from this period denotes manufacture by Young Chang (S indicates manufacture by Samick). From 1979 onwards Young Chang also manufactured acoustic, electric guitars and basses under their own Fenix brand. Young Chang also used "E" letter serial numbers on these Fenix brand guitars. Due to the similarities between Fender models and certain Fenix instruments,Young Chang had licensing problems with Fender and stopped making the Fenix electric guitar models and instead focused on their Fenix acoustic guitars.