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By default, the xmllint command only checks the validity aspects that apply to any XML document, for example, that every start <tag> is matched by a closing </tag>. But not that the actual tag and attribute names are ones recognized by the DITA XML dialect. That extra level of checking requires additional setup. (Instructions pending.)
As mentioned previously, building either HTML or PDF output provides an extra level of validation, producing warnings or errors for any cross-file mismatches between IDs, filenames, and conref / topicref / mapref / href elements. HTML is typically the format that's faster and less memory-intensive to build.
Commit Messages
By convention, to allow for filtering in JIRA reports and email notifications, commits that are purely for documentation updates include the eyecatcher string DOCS inside square brackets. (Literal example with square brackets omitted for the moment because Confluence wants to turn it into a link.)
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