This part of ISO 13216 specifies the dimensions, general requirements and static strength requirements of rigid anchorages for anchoring child restraint systems (CRS) in vehicles. It is applicable to fittings for the installation of CRSs for children with a mass of up to 22 kg, by means of two rigid anchorages positioned in the seat bight area, in passenger carrying vehicles. NOTE 1 This mass limit applies to CRSs where the inertia forces of the child and CRS are transferred via the anchorage system for the CRS. The anchorages may be used for systems for larger children, such as seats where the main forces are transferred through the adult seat belt, provided that the forces applied to the anchorages and the resulting excursions (see 4.2) do not exceed the limits in this part of ISO 13216. To assure compatibility with the anchorages, this part of ISO 13216 also specifies important features of CRSs equipped with rigid attachments, such as critical dimensions of the attachments and general requirements for handling. Supplementary devices, such as tether straps and reaction bars, which may be necessary for specific vehicle configurations or to fulfil performance criteria included in national and international standards and regulations, are not specified in this part of ISO 13216. An interim anchorage system that employs semi-rigid anchorages in the vehicle is described in annex A. Requirements for optional non-rigid attachments on the CRS are given in annex B. NOTE 2 Performance and strength requirements for the homologation of CRSs using attachments according to this part of ISO 13216 are presumed to be specified in other standards and regulations.