Wrapper element for a chemical expression, reaction, equation, etc. that is set apart from the text; includes any number, label, or caption that accompanies the chemical expression.
The following, in order:
<object-id> Object Identifier, zero or more
<caption> Caption of a Figure, Table, etc., zero or one
Any combination of:
One or more of any of:
<attrib> Attribution, zero or one
<permissions> Permissions, zero or one