AllowEmpty | Is it allowed for this item to be unset, empty or null. Default is false. |
AttributeType | Type of the target, used in id resolving. |
RefMember | Name of the class member containing the reference alias/guid/id of the type. Has a default value. If object with the attribute is not class, this value is ignored. |
Required | Is the reference absolute requirement, default is true. |
Validate | Should the reference be validated. Default is true. |