Sir I am not clear with some aspects in Hinged joints

1. As like in Application Manual for Hinged Joint, Torsion should be Rigid, then RX,RY,RZ are Restrained, but u said RX restraint not to give ? can we give rotation for Metallic Bellows.. ?

2. Why we should have to specify RX,RY,RZ restraints even after feeding the value
Torsion- Rigid.