ERHC Energy Inc (ERHE)

[Manti]

Under certain circumstances the shorter Schedule 13G may be used. Shareholders owning more than 5% in non reporting companies such as voluntary filers and Pink Sheets are not required to file a Schedule 13D or Schedule 13G.

http://otclawyers.com/what-is-schedule-13d/

There are others as well, such as the sec rules of 1934 where it all started, which specifically state for stocks listed on an exchange, which does NOT include the OTC.