XML Schema Complete Reference, The

6.9. Model Groups

A model group specifies a pattern for element type instances. There are three kinds of model groups:

• An all model group requires instances of all members of a set of element types or other groups, in no particular order. (Each member may have occurrence restrictions.)

• A choice model group requires an instance of one member of a set of element types or other groups. (Each member may have occurrence restrictions.)

• A sequence model group requires instances of all members of a set of element types or other groups, in a specified order. (Each member may have occurrence restrictions.)

A named model group specifies any one of the other model groups.

6.9.1. The All Model Group

A complex type with complex content specifies an unordered ...