When editing an XML file which is included in another file, it can be desirable for validation to always start at the root file, and not at each included file. For example, you might be writing a user manual using DocBook, with each chapter split into its own XML file. This can be achieved by inserting the following in the first or last 10 lines of each child file:

:xml.root=relative or absolute path of root document

Note that even if this property is specified, the Structure Browser window only shows elements defined in the current buffer. However, when validating an included file, validation errors will be reported for all files included from the root file.