Full Idea
Things that don't exist don't have any properties.
Gist of Idea
Things that don't exist don't have any properties
Source
Jody Azzouni (Deflating Existential Consequence [2004], Ch.4)
Book Reference
Azzouni,Jody: 'Deflating Existential Consequence' [OUP 2004], p.87
A Reaction
Sounds reasonable! I totally agree, but that is because my notion of properties is sparse and naturalistic. If you identify properties with predicates (which some weird people seem to), then non-existents can have properties like 'absence' or 'nullity'.