typexsIDREF

typexsIDREF is an XML schema data type that allows for the referencing of elements defined with the xs:ID type. An xs:IDREF value must match the value of an xs:ID attribute or element within the same document. This creates a link between two parts of an XML document, establishing a relationship where one element's content points to another element's unique identifier. The xs:ID type provides a globally unique name for an element, and xs:IDREF acts as a pointer to that named element. When validating an XML document against a schema that uses xs:IDREF, the schema processor will check if the referenced ID exists. If the referenced ID is not found, the document is considered invalid. This mechanism is crucial for maintaining data integrity and enabling the creation of complex, interconnected data structures within XML. It is commonly used to link related pieces of information, such as referencing a person's record by their ID in a different part of the document, or linking a component to its definition. The xs:IDREF type can also be specified as a list of IDs, denoted by xs:IDREFS, allowing a single element to reference multiple other elements by their IDs.