It is possible for one module (a container module) to contain another module (a contained module). When a container/contained module is viewed online in Control Studio, the opened module appears first in the module path string. The signature policy that is applied for container/contained modules is determined by the policy assigned to the first module in the module path string. For example, suppose that Policy_A is assigned to ModuleA and ModuleA contains ModuleB. If ModuleA is opened, the path string in Control Studio online is ModuleA/ModuleB. Now suppose that a different policy, Policy_B, is assigned to ModuleB. If ModuleA is opened for editing in Control Studio and the parameter changed belongs to ModuleB, Policy_A is applied because it is the policy assigned to the container module ModuleA which appears first in the path string. To have Policy_B applied to ModuleB changes, ModuleB should be opened directly in Control Studio online. These same rules apply when datalinks are added to pictures in DeltaV Operate. The Datalink Browser automatically places the contained module first in the module path. However, if you manually edit a module path, be aware that the signature policy is determined by the module name that appears first in the path string.