This standard BS EN 33:2019 WC pans and WC suites. Connecting dimensions is classified in these ICS categories:
91.140.70 Sanitary installations
This document specifies the connecting dimensions of WC pans and WC suites regardless of the materials used for their manufacture. This document does not apply to siphonic action WC pans and WC suites. NOTE 1 Other connecting dimensions are permitted, e.g. special designs of WC pans, if the manufacturer supplies or recommends the appropriate fittings. NOTE 2 The shape of the appliance in the figures is for illustration only; it in no way prejudices the final shape of the appliance, which is left to the initiative of the manufacturer.