Add precision on limitations

Signed-off-by: Bertrand Rix <bertrand.rix@artelys.com>

Author: obrix

docs/security/inputs.md

@@ -8,7 +8,7 @@ With Open Load Flow only the following remedial actions are currently implemente
 
 - `LoadAction`
 - `SwitchAction`
-- `TerminalsConnectionAction`
+- `TerminalsConnectionAction` (Only supporting actions on branches and three windings transformers terminals)
 - `PhaseTapChangerTapPositionAction`
 - `RatioTapChangerTapPositionAction`
 - `ShuntCompensatorPositionAction`