Oman

Freedom to establish associations is guaranteed, on national foundations, for legitimate objectives, using peaceful means, in a manner that does not contradict with the provisions and objectives of this statute, and in accordance with the conditions and circumstances prescribed by the law.
It is prohibited to establish associations whose activities are hostile to societal order, that are secret, or that are of a military nature. It is not permitted to force a person to join any association. (Art. 40)