PropertyHandle :: IsAttribute - Is property an attribute?
The function returns whether the property handle refers to an attribute (YES) or not (NO). The function returns also NO for shared base structure instances, which are considered rather as relationships than attributes. Embedded base structure instances are, however, considered as attributes. The function returns NO also for generic attributes, which are considered as references.
Return value: Return value ( logical )
The function returns YES when the question was answered positively. Otherwise it returns NO.