An XML Schema prescribes the structure of a type of XML documents. See also information about XML Schema on W3C.
Serna makes it possible to validate the content of an XML document against an XML Schema, automatically generate required elements , provide the user with a list of allowed elements in the current context and prevent insertion of invalid elements. An XML schema is not required, but is a great help for authoring.
If you have a DTD for your documents but do not have an XML schema , you can convert your DTD to a schema using Syntext Dtd2Xs.
In Serna, when you create a new document with a Serna document template, a corresponding schema prescribed by the template is applied automatically. You can also assign the path to some schema other than that prescribed by the selected template.
When you open a document, a corresponding schema is applied automatically by means of a Serna document template that matches the document. You can also open a document with some other template that prescribes another schema.
You can see what XML Schema is currently applied to your document.