Full Idea
There are three possible sources of vagueness: the predicates, the names, and the quantifiers.
Gist of Idea
Vagueness can be in predicates, names or quantifiers
Source
Kit Fine (Vagueness, Truth and Logic [1975], 1)
Book Reference
'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.121
A Reaction
Presumably a vagueness about the domain of discussion would be a vagueness in the quantifier. This is a helpful preliminary division, in the semantic approach to vagueness.
Related Idea
Idea 21598 Austin revealed many meanings for 'vague': rough, ambiguous, general, incomplete... [Austin,JL, by Williamson]