This part of ISO 21549 is applicable to situations in which limited clinical data are recorded on or transported by patient healthcards compliant with the physical dimensions of ID-1 cards defined by ISO/IEC 7810.This part of ISO 21549 describes and defines the limited clinical data objects used in or referenced by patient healthcards using UML, plain text and abstract syntax notation (ASN.1).This part of ISO 21549 specifies the basic structure of the data contained within the data object limited clinical data, but does not specify or mandate particular data sets for storage on devices. In particular the data contained within the data objects in limited clinical data are intended to aid the delivery of emergency care, while being by themselves neither intended, nor fit for purpose, for the total of information provision for the delivery of emergency care.The detailed functions and mechanisms of the following services are not within the scope of this part of ISO 21549, (although its structures can accommodate suitable data objects elsewhere specified):— the encoding of free text data;— security functions and related services which are likely to be specified by users for data cards depending on their specific application, for example: confidentiality protection, data integrity protection, and authentication of persons and devices related to these functions;— access control services which may depend on active use of some data card classes such as microprocessor cards;— the initialisation and issuing process (which begins the operating lifetime of an individual data card, and by which the data card is prepared for the data to be subsequently communicated to it according to this part of ISO 21549).