Prescribed Public API Documentation is not considered by SQ v5.6

SonarQube version: 5.6
Programming Language: C
Issue with ‘Public API Documentation’ metric.

As per the documentation, below comments are valid for Public API, however SonarQube still showing this as Public Undocumented API.
/**

  • Comments
  • Comments
    */
    API int fun(const char *id, char **key);

Please help us understand what we are missing.

We have even tried out the below way of Public API Documentation:
/*!
*Comments
*Comments
*/

///Comments
///Comments
///Comments

//!Comments
//!Comments
//!Comments

Hi,

Welcome to the community!

SonarQube 7.9.1 is the latest version and current LTS. You’re two LTS versions and several analyzer versions behind. You’re going to have a very hard time finding help on anything to do with 5.6. You should upgrade at your earliest convenience and come back to us if you’re still having problems.

 
Ann