BPMN21 — Artifact used as an example for FlowElement

On page 71 of the spec, in the Category chapter, in the Table 8.23, the attribute categorizedFlowElements of the CategroyValue element is descibed as follow :

categorizedFlowElements: FlowElement [0..*]
The FlowElements attribute identifies all of the elements (e.g.,Events, Activities, Gateways, and Artifacts) that are within the boundaries of the Group.
But Artifact is not a FlowElement, so it must not appear as an example of the latter