Kode ini dikeluarkan oleh The Society of Plastic Industry pada tahun 1988 di Amerika Serikat dan diadopsi pula oleh lembaga-lembaga yang mengembangkan sistem kode, seperti ISO (International Organization for Standardization).
Secara umum tanda pengenal plastik tersebut :
- berada atau terletak di bagian dasar,
- berbentuk segi tiga,
- di dalam segitiga akan terdapat angka,
- serta nama jenis plastik di bawah segitiga,
Ada berapa jenis tanda pengenal plastik itu?
Ada 7 buah kelompok tanda pengenal jenis plastik, serta 3 jenis tambahan, sehingga total ada 10 jenis tanda pengenal plastik loh.

"And I thought my jokes were bad!" sneers Heath Ledger's Joker in The Dark Knight. The character is today at the centre of a row about dodgy humour, but it's got nothing to do with his gags. A poster has been appearing across Los Angeles and other parts of the United States in which President Barack Obama is depicted as the supervillain, with the word "socialism" written beneath his made-up face. Who has been pasting it up is not widely known but it marks the first time a negative representation of Obama has gained mainstream traction, as well as the American right's first successful use of street art. But is it dangerous? And is it any good?