The name of the General Entity that holds the file name and the type of notation for the graphic to be inserted.
This attribute is used to implement the style of graphics insertion that is currently the most popular for XML products. The graphic is held in an external file and pointed to from the XML file. The pointing is done by a general entity. The value of this attribute is the name of the general entity. The named entity both gives the type of graphic file and provides a pointer (which may be direct or indirect) to the file that contains the graphic.
