You can import an XML document that references a schema file, and you can specify a schema file in your Structured Application, to use for validating a document upon export to XML.
For a specific XML document, you can include the path
of the schema file in the XML using the attributes @noNamespaceSchemaLocation or @schemaLocation depending
on whether your schema includes a target namespace or not.
To specify a schema file for use in exporting XML, modify
the structapps.fm file. Use the <Schema> element
as part of the <XMLApplication> to provide
the schema file path for export.
Open the XML file in Adobe FrameMaker using a Structured Application. Edit it.
Save the XML using a Structured Application. The <Schema> element
in the structapps.fm file is output in the
file and validation is performed against it.
In this workflow, a DTD is generated automatically as an intermediary file from the schema given in the XML document, and you do not modify it. However, you can also use a schema file to generate an EDD. See Generate an Element Catalog (EDD) from a Schema.