<moduleRef>

<moduleRef> (module reference) references a module which is to be incorporated into a schema.
Moduletagdocs — 22 Documentation Elements
AttributesIn addition to global attributes
keythe name of a TEI module
Status Optional
Datatype 
xsd:NCName
url(uniform resource locator) refers to a non-TEI module of RELAX NG code by external location
Status Optional
Datatype 
data.pointer
Used byschemaSpec model.oddRef
May contain
tagdocs: content
Declaration
element moduleRef
{
   att.global.attributes,
   ( attribute key { xsd:NCName }? | attribute url { data.pointer }? ),
   content?
}

<sch:pattern name="testschemapattern">
<sch:rule context="tei:moduleRef">
 <sch:report test="* and @key"> child elements of moduleRef are only allowed when an external module
   is being loaded
 </sch:report>
</sch:rule>
</sch:pattern>
Example
<moduleRef key="linking"/>

This embeds the linking module.

Note
Modules are identified by the name supplied as value for the ident attribute on the <moduleSpec> element in which they are declared. A URI may also be supplied in the case of a non-TEI module, and this is expected to be written as a RELAX NG schema.
The effect of this element is to make all the declarations contained by the referenced module available to the schema being compiled.