They still sell zip cord here, but it wasn't used much for at least 20 years, mostly for botched repairs and cheap speaker wiring. Nowadays the reels carry a note saying: 42V max!, so it's only for use with SELV. The most common 2conductor replacement cord is the round double-sheathed one. Flat double-sheathed (NISPT) is pretty hard to get by, only with a molded-on Euro plug and in most cases a cord switch.
