Proposed resolution, February, 2018:

Change 7.5.5.2 [expr.prim.id.unqual] paragraph 1 as follows:

An identifier is only an id-expression provided if it has been suitably declared ( Clause 9 [dcl]) or if it appears as part of a declarator-id (9.3 [dcl.decl]). [Note: For operator-function-ids, see...