Please do not cross-post responses to this proposal because unfortunately discussions do not span mailing lists very easily. I look forward to opinions on both of the included lists.
Inclusion allows documents and parts of documents to be reused automatically in multiple documents.
It should be considered a structured alternative to XML's text entity mechanism. There are many reasons for wanting to include text. For the purposes of this document, we will refer to the former as inclusion and the latter as transclusion. For instance you might want to include boilerplate text for a copyright. In that case, the original context is not useful.