Full Idea
Facts are the sort of things that are asserted or denied by propositions, and are not properly entities at all in the same sense in which their constituents are. That is shown by the fact that you cannot name them.
Gist of Idea
You can't name all the facts, so they are not real, but are what propositions assert
Source
Bertrand Russell (The Philosophy of Logical Atomism [1918], p.235), quoted by Bernard Linsky - Russell's Metaphysical Logic 2.2
Book Reference
Linsky,Bernard: 'Russell's Metaphysical Logic' [CSLI 1999], p.20
A Reaction
[ref to Papers vol.8] It is customary to specify a proposition by its capacity for T and F. So is a fact just 'a truth'? This contains the Fregean idea that things are only real if they can be picked out. I think of facts as independent of minds.