according to the TDG, <set> allows another <set> or <book>, but no <article>. I would like to propose to include article as a possible child of <set> in the DocBook schema.
Documentation for software products often contains not only Reference Manuals, but also Whitepapers and Quick Starts. The latter two are
In order to bundle the complete product documentation into a <set> to allow cross-linking, it currently is necessary to bundle the <article>s
into a <book>. This is unfortunate, when
a) only having one article that needs to be added,
b) a number of articles covering not-related topics
c) generating HTML/ePUB for the whole set (see TOC)
For this reason, I think, an <article> would perfectly fit as a possible child of <set>. It avoids the need to create additional book structures
just for the sake of being able to add articles to a set.