Both Source and Tree editors allow you to attach an XML schema or DTD from the toolbar.
To choose from a list of entries in the XML catalog, choose an entry from
list.Figure 20-3 Attach an XML Catalog
To reference an XML schema on disk, choose XML Schema, then specify the namespace URI and the file’s disk location.
Figure 20-4 Attach an XML Schema
To reference a DTD on disk, choose DTD, then specify the Public and System IDs and the file’s disk location:
Figure 20-5 Attach a DTD