Abstract class for that is the base class for all particle types (e.g. System.Xml.Schema.XmlSchemaAny).
See Also: XmlSchemaParticle Members
Particle types are usually interchangeable. Particle can be a local element declaration or reference to a global element declaration (element), a compositor (sequence, choice, or all), a reference to a named content model group (group), or an element wildcard (any).