A document title
Each TITLE may occur only once
A document subtitle
Subtitles as well
The document header is once only.
All parts of decoration may occur singly.
Stefan Merten
Should propagate to docinfo
PCDATA
Some elements may contain only #PCDATA. They need to propagate changes
up. These are the references of
CITA
CITATION
and footnotes
1
2
.
Only once only
Other elements may occur only once and thus need to propagate their
changes up or down.
Titles and subtitles of any kind
See this section and document title / subtitle
Transitions
They have no children which could change.
Parts of definition lists
Defined term
Need to know
Explanation
Unknown term
Definition of term is also only once
Term becomes known
Parts of field lists
Only once
Single
Some content
Another field
Field body is also only once
Body of a field.
The attribution of a citation
To be or not to be!
Mozart
Shakespeare
Parts of a figure
The caption of a figure
Picture title
Several parts of a table
Left
Right
Row
Entry
only
once
Changed
entry
Also colspec, thead and tbody but they are ignored here.
PCDATA
and
only once
Some elements are of both types.
Some old description - still description may
appear only once
A NEW DESCRIPTION
A changing option_string must propagate to option
The option_group and the description may also appear
only once
THE DESCRIPTION AS WELL AS THE OPTION_GROUP MUST BE SINGLE.
The label of a citation.
The label of a footnote.
The label of a citation.
The label of a footnote.