(Note: This question is marginally related with this one.)
I am looking for a word to describe how obligatory something is. It may be mandatory, recommended or optional (given the context, more categories could apply).
The best options I have in mind are quite verbose:
These words reflect how binding/obligatory/mandatory a feature is.
These words reflect whether the feature is mandatory, recommended or optional.
I would like to use a single word that reflects that quality. A header that could cue in any of these values, if that's clearer. But I find these options jumping between awkward and plainly wrong:
These words reflect the bindingness of a feature.
These words reflect the obligatoriness of a feature.
Is there a simpler or more common word for this concept?