-The form or type of the relevant legal instrument, i.e. is it a formal treaty that requires formal ratification and therefore taken more ‘seriously’ by states?
-Are provisions of the legal instrument expressed in mandatory language, e.g. ‘shall’ or ‘must’ as opposed to ‘should’ or ‘aim’ and the use of phrases like ‘as appropriate’ or ‘to the extent possible in view of national circumstances…’
-The specificity with which the expected behaviour is expressed. Does it describe an outcome in sufficient detail (meet target of XY by XY) or leave plenty of room for interpretation (‘variety of sources public and private…).
-The potential enforceability of obligations, i.e. whether the treaty contains compliance procedures, mechanisms, or event sanctions, the stringency and credibility of those mechanisms.
Thanks to the Legal Response Initiative for this explainer.