PrimaryItemDeclaration

Primary item declaration. It must be in the xbrli:item substitution group but neither in the xbrldt:hypercubeItem nor in the xbrldt:dimensionItem substitution groups.

A primary item may be used as explicit dimension member.

Note that in the Dimensions specification, primary item declarations and domain-member declarations have exactly the same definition! Although in a taxonomy the dimensional relationships make clear whether an item plays the role of primary item or of domain-member, here we call each such item declaration a primary item declaration.