XML is a standard for describing hierarchical data structures.
XML is used in MD Link to define a common data format for the exchange of data between dissimilar applications by creating a template (schema) that describes the structure of the data, and a means of transforming each application’s data to the common format. This guarantees that the two applications have the same understanding of the significance of each piece of data.
The schema describes each of the pieces of data (XML Elements) and their characteristics (XML Attributes), and specifies which elements are required and which are optional, and how they are related to each other. For example, the schema may specify that a patient record includes a required address that consists of a required street name (alphabetic), an required street number (numeric), an optional second street description (alphabetic), a required city (alphabetic), an optional state/province (alphabetic), a required postcode (alphabetic), and a required country (alphabetic).
In the windows used to build the data mapping between two applications, MD Link displays the appropriate schemas to guide the mapping of individual data elements from one application to the other.