For all other Methods on Condition objects we define:
"Normally, the MethodId passed to the Call Service is found by browsing the Condition instance in the AddressSpace. However, some Servers do not expose Condition instances in the AddressSpace. Therefore all Servers shall allow Clients to call the AddComment Method by specifying ConditionId as the ObjectId and the well known NodeId of the Method declaration on the ConditionType as the MethodId. The Method cannot be called on the ConditionType Node."

We are not saying anything about this issue for the methods on the ShelvingState state machine.

To call a method on a ShelvingState object based on the standard Method definition, the client needs the NodeId of the ShelvingState object and the NodeId of the method below the ShelvingState object e.g. Unshelve().

Both information is unknown. For the method we can also require support for the Method NodeId from the type definition but there is currently no way to get the NodeId of the ShelvingState object if the Condition object is not visible in the address space.