Does This Entity Make Sense?

I've been going though some combinations of Data Element Terms that are
possible, and came across the following example:

PurchaseOrder_Customer. Code

My question is: Is this a valid entity according to the Core Components
methodology? More details:

- If we had an entity named "Customer. Code" (Property Term="Customer",
Representation Term="Code"), according to CCTS it would not be
considered a BCC because there is no Object Class. For our purposes, we
may consider this a "Base BCC" from which BCCs are constructed.

- The "PurchaseOrder" qualifier above is a Property Term Qualifier, not
an Object Class Qualifier (because there is no Object Class) - which I
believe makes this entity invalid according to CCTS (unless we
considered it a "Base BBIE"?). But an entity named
"PurchaseOrder_Document. Customer. Code" would be valid according to
CCTS because it makes sense to have "PurchaseOrder" as an Object Class
qualifier.

Can anyone offer additional insight into this?

Thanks,
Joe