For the purposes of design, calculation and representation, all CAD planning systems and calculation and data management programs require the catalogue data of building services products or system components to be available in machine-readable form. The series of standards VDI 3805 describes the uniform data format, independent of manufacturers and electronic data processing systems, for the provision of catalogue data. The standard specifies rules for the exchange of product data in computer-aided planning processes for the building services product range of pipes and fittings. It is based on the standard VDI 3805 Part 1.