This document specifies a child seat presence detection system that enables child seats placed on any passenger seats to be automatically detected where a child is at risk from an active airbag. The system provides the option of using additional information about the orientation of the child seat. This document specifies the minimum functional requirements in order to ensure compatibility between child seat presence and orientation detection system (CPOD) child seats and CPOD passenger seats. Compatibility measurements and labelling requirements complement the obligatory specifications of this document. This document also provides design recommendations which are not compulsory when claiming compliance with ISO/TS 22239. However, these recommendations, based on experience of proven designs, provide useful guidance to designers to avoid erroneous designs and thus, enable designers to reduce time and cost of CPOD development. The tell-tale "child seat detected" required for a CPOD vehicle, the specific labelling required for a CPOD vehicle and CPOD child seat and the detailed information about the CPOD system functionality required for owner's manuals of CPOD vehicles and CPOD child seats will mitigate considerably the misuse probability. The document does not provide a failsafe physical mechanism that prevents the installation of non-CPOD child seats in a CPOD vehicle or vice versa. ISO/TS 22239 applies only to child restraint systems in which the child is orientated in the forward or rearward driving direction. NOTE 1 Throughout this document, the term "child seat" is used as an abbreviation of "CPOD child seat". NOTE 2 Throughout this document, the term "passenger seat" is used as an abbreviation of "CPOD-equipped passenger seat".