This European Prestandard specifies a procedure for the registration of coding schemes used in health care for any purpose. It also specifies the allocation of a unique Health Care Coding Scheme Designator (HCD) to each registered coding scheme. A code value can thus be given an unambiguous meaning by association with an HCD. The method by which an HCD and a code value are associated is not defined by this standard. The association is achieved in any manner appropriate to the syntax used.