New attribute syntaxes require additional code to be implemented on the PingDirectory Server. If you need new syntax definitions, contact your authorized support provider for assistance.

The formal specification for attribute types is provided in RFC 4512, section 4.1.5 as follows:
SyntaxDescription = "(" wsp 
numericoid	              ; Object identifier 
[ sp "DESC" sp qdstring ] ; Description 
extensions wsp ")"	      ; Extensions followed by a white space and ")"