EN 13724 [documento eletrónico] : postal services; : apertures of private letter boxes and letter plates; : requirements and test methods / EUROPEAN COMMITTEE FOR STANDARDIZATION
EN 14012 [documento eletrónico] : Postal services - quality of service - complaints handling principles
EN 13850 [documento eletrónico] : postal services - quality of services - measurement of the transit time of end-to-end services for single piece priority mail and first class mail