Each document in Serna belongs to some document type that is associated with a particular set of metadata. Metadata provides additional information that is necessary for work with a document, such as XML Schema and stylesheet, and files that control the GUI layout and some functional settings.
On opening a document, metadata can be retrieved from different sources. It is convenient to associate metadata with a document type by means of Serna document templates. Serna document templates match documents according to special rules.