The following are descriptions of valid characteristics, identifiers,
 and status attributes:

 CHARACTERISTICS

 DNS$CTS

 Specifies the creation timestamp (CTS) of the directory of which
 this replica is a copy.

 DNS$LastSkulk

 Records the timestamp of the last skulk that began processing this
 particular replica of a directory.  This will be zero for read-only
 replicas since they do not start processing for a skulk.

 DNS$LastUpdate

 Records the timestamp of the last update to any attribute of the
 replica, or any change to the contents of the replica, including
 object entries, child pointers, and soft links.  This will be zero
 for read-only replicas.

 DNS$ReplicaType

 Specifies the replica type of a directory.

 DNS$ReplicaVersion

 Specifies the replica version of a directory.

 DNS$RingPointer

 Specifies the creation timestamp (CTS) of all clearinghouses
 containing another replica of this directory.

 IDENTIFIER

 DNS$Epoch

 Identifies a replica as part of a directory's complete set.

 STATUS ATTRIBUTE

 DNS$ReplicaState

 Specifies the internal state of a replica. When you create or delete
 a replica, it goes through various states.