Henri Hudrisier points out that the following sentence at the start of 10.6 needs some attention ""The summary element may be used in conjunction with <msItem> or <msItem> elements where information is provided both about the content as a whole, and about individual items within it."
This is not merely pleonastic, but also misleading: it suggests that you can put a <summary> inside an <msItem> which is not the case. What it is trying to say is that you can provide <msItem>s as well as a <summary>, as the following example shows.
I have revised the passage as follows:
<p>The <gi>summary</gi> element may be used in conjunction with
one or more <gi>msItem</gi> elements if it is desired to provide both
a general summary of the contents of a manuscript and more detail
about some or all of the individual items
within it. It may not however be used within an individual
<gi>msItem</gi> element. </p>