This property is read-only..

Indicates whether the macro is referenced by a part. When customizing the insert center, you can use this property as a filter criterion for window and symbol macros.This filters out all macros from the "Window macros / symbol macros" folder that are used in devices and are therefore already displayed in the "Devices" folder.

0 = Unknown (value could not be determined)

1 = Yes

2 = No

Reference

MacroEntryPropertyList Class
MacroEntryPropertyList Members