Which documentation system uses this format?

Question

#pragma region INFO
/*
 * @ FUNCTION: GetSubStrBetween
 *
 * @ PARAMETER(s):
 *      [1st] std::string &in_Str = This paramter takes in a std::string, which
 *            is the string that contains the unknown sub-string.
 *
 *      [2nd] std::string in_A = This parameter takes in a std::string, which
 *            will be the beginning point of the unknown sub-string.
 *
 *      [3rd] std::string in_B = This parameter takes in a std::string, which
 *            happens to be the ending point of the unknown sub-string.
 *
 *      [4th] std::string in_out_SubStr = This parameter takes in a std::string,
 *            which will contain the unknown sub-string.
 *
 *      [5th] bool in_opt_Append = This optional* parameter takes in either a true
 *            or false value. If in_opt_Append = true, in_out_SubStr (see 4th
 *            param.) will append the unknown sub-str. Else, in_out_SubStr will be
 *            equal to the unknown sub-str. Note: The default value is false.
 *
 * @ RETURN VALUE(s):
 *      false = This function returns a false value because...
 *              - The length of in_Str/in_A/in_B is equal to 0.
 *              - The length of in_A/in_B is greater than or equal to the length
 *                of in_Str.
 *              - The length of in_Str is smaller than length of in_A + the length
 *                of in_B.
 *              - Unable to find in_A/in_B.
 *      true = Successfully found and return the unknown sub-str to in_out_SubStr.
 */
#pragma endregion INFO

It's clean and seems like very useful format.

Answer 1

#pragma region <region_name>
#pragma endregion <region_comment>

is simply the collapsible region stuff in Visual Studio, allowing you to collapse or expand blocks when looking at your source in outline mode.

The text inside it is largely irrelevant to Visual Studio and doesn't match the usual suspects like Doxygen, Ghost Doc or the built-in Visual Studio stuff.

Failing notification from the author of that code (unfortunately, they haven't been seen here since May 2013), you may just have to accept they were fastidious about their comments, unless someone comes along who knows the format off the top of their head.