It is possible for a referential member of a collection to carry its own properties, distinct from those of the resource it refers to. A referential member of a collection also inherits the properties of the resource it refers to. Documents and references have different access rights, and sometimes one is wider than the other. After the properties are copied, the owner of the target resource no longer has means to control access on the properties. ACAP has had problems with 'inheritance'.
Referential members are like symbolic links.
But symbolic links do not in general have the 'properties' of their target. Their owner, size, and date modified all differ. 3.1.10 A listing of the members of a collection shows both the internal members and the referential members. 3.1.11 Servers are encouraged to maintain referential integrity for referential members as far as possible, but are not required to do so. This requirement led to a re-opening of the integrity issues of 3.1.4.