Can Redfish implementation change content of AllowableValue?

No, we've typically not seen that sort of behavior, and that could be seen as confusing for some users in my mind.

One of the other issues with this potentially is it can cause issues with simple maintenance scripts. For example, a script might blindly walk all systems in a rack and perform a ComputerSystem.Reset with the ResetType "ForceOff". If a system is already powered off, the user doesn't want an error message because the system is off; from a REST perspective, the system is already in the desired state, so nothing needs to be done. We've added this text in the spec a few releases ago to help highlight this:

> If an action requested by the client has no effect, such as a reset of a ComputerSystem where the ResetType parameter is set to On and the ComputerSystem is already On , the service should respond with the HTTP 200 OK status code and return the NoOperation message from the Base Message Registry.