The specification about FPolicy servers

Could you let me know where can I find the documents for FPoilicy servers?
We would like to use FPolicy to restrict file access on strage system.
As mentioned in the document; 'File Access and Protocols Management Guide' in '8.2.2 7-Mode Documentation',
we understand the external applications can register as FPolicy servers.
However I cannot find the description how to develop FPolicy servers and the specification of RPC
between storage system and FPolicy servers.