A wrapper for a document-level element that may contain its own metadata, front matter, and back matter, and that will contain, in addition, one or more complete standards (<standard>) or other adoptions. When a standard is adopted, sometimes the adopting organization wraps their own metadata, front matter, and back matter around a standard, producing a combined, nested document.
The following, in order:
Any one of:
The following, in order:
The following, in order:
One or more of any of:
<back> Back Matter, zero or one