Classifier

He was a model of anal defensiveness: fastidious in his dress and appearance, a collector and putter of things in order, a classifier and labeler.

A classifier can have several types of extra information attached to it via a UML mechanism called adornments.

The owner scope of a feature specifies whether the feature appears in each instance of the classifier or whether there is just a single instance of the feature for all instances of the classifier.

The figure also shows that instances can be associated with a classifier Behavior, which represents the behavior that active objects start executing when created.