I have to extend the data model for material MDG.Do anyone have an idea why Table T438A and Table T439A as dipcted below have different relationship to the MARC table one type3 entity(T438A) and other one as an attribute(T439A). I understood that when there is an additional key field in the type1 or type 4 entities, type3 entity should be created for that key field, so there is a justification for T001W and T024D but not for the case mentioned above I tried to find about this but didn't get any relevant information.
Please help me understand.
Thanks and Regards,
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