in identificational information packaging, the information which is identified as the filler for the open part of the presupposed open proposition. Example: in It was Jack who stole my cookies!, the presupposed open proposition is X stole my cookies, and the filler of X is Jack -- i.e. X = Jack. The focus may be any part of the information in the clause, not just an argument. The term focus construction is sometimes used as a synonym for identificational construction, but we avoid that usage here. (Section 11.4.1)