The cmis:cmisProperty complex type and its descendants restricts a providers ability to return extended information elements as children of this element. This is useful when vendors want to provide additional information associated with a property and its value that is best modeled as extension elements.

For example, if a provider has a string property that represents a user, they may want to support the following in order to embed information about the user:

<cmis:propertyString propertyDefinitionId="cmis:createdBy" localName="cmis_createdBy" displayName="Created By">
<cmis:value>John Doe</cmis:value>
<directory:displayName>John Doe<directory:displayName>
<directory:principal>jdoe<directory:principal>
<directory:mail>jdoe@example.com<directory:mail>
</cmis:propertyString>

The cmis:cmisProperty extended elements do support cmis:cmisUndefinedAttribute attribute group.

They provide more flexibility and support <xs:any namespace="##other" minOccurs="0" maxOccurs="unbounded" processContents="lax"/> as a valid child element.