It is important to understand the origin of the IMC rating. It was introduced to compensate for changes in the law that prohibited pilots from flying in IMC outside controlled airspace, glider pilots retained that right. The IMC was variable in that it did not mandate equipment or approaches but allowed alternatives with the recommendation of additional training if different approaches are to be flown. In practical terms it is very difficult to complete IMC training without ADF even though it is not mandated especially as VDF has now largely disappeared.