Synonym mapping allows a node name to be determined from a Phase IV
 synonym assigned to that node.

 For directory services that support hierarchical naming, this is done by
 setting up directories and links within those directories, based on the
 synonyms assigned to the nodes in the network.  Each link then points
 to the node name associated with the indicated synonym.

1  –  DECdns

 Soft link names are used to map synonyms to their respective node
 names.

 The default value for the synonym mapping directory in the DECdns
 directory service is:

   .DNA_NodeSynonym

 The directory name can be changed for a single command using the
 REVERSE_MAPPING parameter, or for all commands using the SET DEFAULT
 command.

 This directory contains the actual soft link names.  The name structure
 is:

   .DNA_NodeSynonym.<synonym>

 Where:

   <synonym>     is the Phase IV synonym name.

 For example, for the synonym "MYSYN", the fully specified soft link name
 would be:

   .DNA_NodeSynonym.MYSYN

2  –  Local

 The Local Naming Database does not make use of synonym mapping for
 mapping Phase IV synonyms to names.  Instead, the Phase IV synonyms
 are treated as keys within the indexed Local Database file.

3  –  Phase IV

 The Phase IV Database does not make use of synonym mapping for mapping
 Phase IV synonyms to names.  This is because Phase IV synonym names are
 the only names allowed in the Phase IV Database.