Allowed attributes for a given domain are represented by members in MRCM attribute domain reference sets. The referenced component of an attribute domain member is a concept from the Attribute hierarchy. Each domain that an attribute is allowed in is denoted in a separate member by the Domain field. The exact domain constraint is defined by the MRCM domain reference set member referencing the concept in the Domain field.
Attribute domain members also include information regarding the attribute's overall and in-group cardinality and whether they're meant to be used in a group or not.
For more information regarding MRCM attribute domain members see the official documentation.
