This part of ISO 21549 establishes a common framework for the content and the structure of common objects used to construct data held on patient healthcare data cards. It is also applicable to common objects referenced by other data objects.This part of ISO 21549 is applicable to situations in which such data is 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 specifies the basic structure of the data, but does not specify or mandate particular data-sets for storage on devices.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 initialization 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).The following topics are therefore beyond the scope of this part of ISO 21549:— physical or logical solutions for the practical functioning of particular types of data cards;— how the message is processed further ‘downstream’ of the interface between two systems;— the form which data takes for use outside the data card, or the way in which such data is visibly represented on the data card or elsewhere.