Even though the paragraph 1(b) rights can be contractual the Official
Commentary points out that: ‘the priority (in the case of 1(a)) or right of detention orarrest (in the case of 1(b)) must arise under the national law of the declaring State.
Ibid, para 4.273. The Official Commentary in
paragraph 4.276 has detailed comments on the types
of governmental units or providers of public services,
whether State, State entity, intergovernmental or private
organization, and as to which rights to arrest or detain
can be preserved