The design of the Y-shape Hull has been patented by DAMEN. They currently own the patents for many countries worldwide. Together with Deen Shipping and Rensen-Driessen, they also hold the licensing rights of the Y-shape Hull design.
The Y-shape Hull design is approved by the Central Commission for the Navigation of the Rhine, (CCNR). It is also recognized by all classification societies like Lloyds Register, Bureau Veritas, and Germanischer Lloyd, and has been included in the ADN, European Agreement Concerning the International Carriage of Dangerous Goods by Inland Waterways.
For more information on inland vessels regulations, please take a look at chapter 9.3.4 of the ADN on alternative constructions. Which you can read here (part 9: rules of construction).