Full Idea
The core of haecceitism is the view that the transworld identity of particulars does not supervene on their qualitative features. ...The simplest expression of it is that particulars lack essential properties.
Clarification
'Haec' is Latin for 'that'
Gist of Idea
Haecceitism says identity is independent of qualities and without essence
Source
Alexander Bird (Nature's Metaphysics [2007], 4.2.1)
Book Reference
Bird,Alexander: 'Nature's Metaphysics' [OUP 2007], p.71
A Reaction
This seems to be something the 'bare substratum' account of substance (associated with Locke). You are left with the difficulty of how to individuate an instance of the haecceity, as opposed to the bundle of properties attached to it.