Establishment of a link to non SGML data, e.g. graphics, video, or non-SGML text.
Used for inclusions of, or references to all non-SGML data.
The first anchor point, 'ReferencePoint', is always a 'infoga.nonsgml' element. The second anchor point, 'ReferencedNonSGML', is one or more entities containing the non-SGML data (e.g. the graphics, a video clip, etc). If it consists of several entities they must contain identical or alternative information, e.g. a figure that exists in several storage formats that may be substituted for each other depending on system capabilities.
For further explanations, see the HyTime standard (ISO 10744), clause 9.2.1.