Remove a node registration from a directory service.  This is used when
 a node is no longer available in the network, and the node registration
 needs to be removed from a directory service.

1  –  Directory Service

 This field specifies the directory service that contains the node
 registration to be deregistered.  The service must be one of:

     LOCAL
     DECDNS
     PHASEIV

 The service type can be abbreviated, as long as the abbreviation is
 unique.

2  –  Node Name or Address

 This field specifies the identification of the nodes to be deregistered.
 The node identification can be one of:

     The fully specified name for the node in the directory service.
     The Phase IV synonym for the node.
     One of the NET or NSAP addresses for the node.
     The Phase IV address (and optional Phase IV prefix) for the node.

 Wildcards are allowed in names and addresses.

2.1  –  Names

 The node to be deregistered can be specified using its full name or its
 Phase IV synonym.

 The syntax of a fully specified name depends on the directory service
 being used.  Examples of fully specified names might be:

     For Local:      MailHub
     For DECdns:     MyCo:.Sales.MailHub
     For Phase IV:   MLHUB

 An example of a Phase IV synonym for any of the above might be:

     MLHUB

 Wildcards are allowed in the node name using an asterisk (*).  For
 example:

     For Local:      Mail*
     For DECdns:     MyCo:.Sales.Mail*
     For Phase IV:   ML*

 The wildcard character can come anywhere in the last part of the name.
 Only a single wildcard character is allowed.

2.2  –  Addresses

 The node to be deregistered can be specified using one of its NETs (or
 NSAPs), or its Phase IV address.

 An NET is an NSAP address value with an N-Sel value of "00" (indicating
 that it is independent of the type of transport service in use on the
 node).  If you specify an NSAP instead of an NET, it is converted to an
 NET before it is used.

   DNA format:  <afi>:<idi>:<predsp>-<locarea>:<nodeid>:00
   OSI format:  <afi><idi>+<predsp><locarea><nodeid>00

 Examples of NETs might be:

   DNA format:  39:840:0001:AA-00-04-00-05-04:00
   OSI format:  39840+0001AA000400050400

 If the node has a Phase IV address, that can be used instead of an NET.

   Format:      <area>.<nodeid>
                <area>.<nodeid>+<prefix>

 This is internally converted to an NET, using the Phase IV prefix value.
 The Phase IV prefix value can be specified with the Phase IV address,
 or set as a default using the preferences form.

 Examples of a Phase IV address might be:

   1.5                                Uses the default Phase IV prefix
   1.5+39:840                         Uses an explicit Phase IV prefix

 Wildcards are allowed in the NET or Phase IV address using an asterisk.
 The wildcard character must replace either the node id, or the local
 area and the node id.  For an NET containing a wildcard, do not specify
 an N-Sel value.

   39:840:0001:*   (or 39840+0001*)   Wildcard the node id
   39:840:*        (or 39840+*)       Wildcard the local area and node id

   1.*                                Wildcard the node id
   *.*                                Wildcard the area and node id

3  –  Display Node Information

 This field allows you to see the list of nodes to be deregistered before
 the actual deregistration is done.

 If you answer no, you are immediately asked if the specified nodes are to
 be deregistered, or if the operation is to be cancelled.

 If you answer yes, you are presented with the names and addresses of the
 nodes, before you are asked if the nodes are to be deregistered or if the
 operation is to be cancelled.