DTD Attribute Types - IDREF

• Type: ID
• Type: IDREFS

The attribute type of IDREF is used for referring to an ID value of another element in the document.

Syntax:

Example:

Valid XML - The following XML document would be valid, as it conforms to the above DTD:

Invalid XML - The following XML document would be invalid. This is because the manager_id attribute of the second element contains a value that isn't the same as a value of another element that contains an attribute with a type of ID:

• Type: ID
• Type: IDREFS