Full Idea
It is in general not the case that the reference of a name is determined by some uniquely identifying marks, some unique properties satisfied by the referent and known or believed to be true of that referent by the speaker.
Gist of Idea
A name's reference is not fixed by any marks or properties of the referent
Source
Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 3)
Book Reference
Kripke,Saul: 'Naming and Necessity' [Blackwell 1980], p.106
A Reaction
He is proposing, instead, his historical/causal theory. There does seem to be a problem with objects which have a historical 'baptism', and then entirely change their properties. Kripke us desperate for a simple account of reference.