Full Idea
My 1980 paper said properties are individuated by causal features - the contribution they make to the causal powers of things, and also how their instantiation can be caused. Collectively, these causal features are the essence of a property.
Gist of Idea
Formerly I said properties are individuated by essential causal powers and causing instantiation
Source
report of Sydney Shoemaker (Causality and Properties [1980], I) by Sydney Shoemaker - Causal and Metaphysical Necessity
Book Reference
Shoemaker,Sydney: 'Identity, Cause and Mind' [OUP 2003], p.409
A Reaction
The later paper worries about uncertainty over individuation. The view I favour is that 'powers' is a much better term for what is basic, and this allows 'properties' to be the complex notion we use in real life, as innumberable power-combinations.