SCOPE AND FIELD OF APPLICATION Differences@ where they exist@ are shown in the appendix with associated rationale. This SAE Recommended Practice defines the most commonly used terms for piston rings. These terms designate either types of piston rings or certain characteristics and phenomena of piston rings. The terms and definitions apply to piston rings for reciprocating internal combustion engines and phenomena of piston rings. The terms and definitions apply to piston rings for reciprocating internal combustion engines and compressors working under analogous conditions. An addendum is included which lists equivalent terms in English. French@ Russian@ German@ Spanish@ Portuguese@ Italian@ and Japanese.