DIN SPEC 1177 is the national version of the international document CEN ISO/TS 14253-4. This part of ISO 14253 outlines the main assumptions behind the theoretically ideal decision rules established in ISO 14253-1. It discusses why these rules are default rules and what considerations should be taken into account before applying different decision rules. ISO/TS 14253-4 has been prepared by ISO/TC 213, Dimensional and geometrical product specifications and verification. On the national level the responsible Committee is NA 152-03-02 AA "CEN/ISO Geometrische Produktspezifikation und -prüfung" ("CEN/ISO Dimensional and geometrical product specification and verification").