Locates one or more SGML element, by their ID attribute value
Used when one or more elements are located. The content of this element must be identical to the value of the located element's ID-attribute. The module in which the elements arelocated is identified in attribute "docorsub", pointing at an entity declaration in the same instance as this element.
For further explanations, see the HyTime standard (ISO 10744), clause 8.3.2.2.