This extension is used to provide a way to get and set a documentation for an element of a specific meta-model. A generic implementation using EAnnotation on EModelElement is used if no other implementation is found for the current meta-model. The nsURI of the meta-model for which this implementation applies. The implementation for the specified meta-model. This attribute is used to specify the priority of the contributed documentationManager. The documentationManager with the higher priority will be used. The behavior is unspecified if more than one documentationManager have the same modelNsURI and the same priority. Default value is Lowest.