Groups and substitution groups

One way an XML Schema allows the creation of reusable content is by using named model groups. These global groups can be referenced throughout a schema.

Substitution groups are a flexible way to designate element declarations as substitutes for other element declarations in a content model. New element declarations can easily be designated as substitutes from other schema documents or namespaces without changing the original content model.

Groups and substitution groups are represented in the type properties with the value XML_GROUP.