Copyright Holder Elements
Elements that can be included along with data characters inside the content model of the <copyright-holder> element.
The subscript and superscript elements were included in this parameter entity because the dot com revolution has produced some unusual business names.
<!ENTITY % copyright-holder-elements "| %institution-wrap.class; | %subsup.class; | %x.class;" >
| institution | institution-wrap | sub | sup | x