In "the principles of mathematics" russell accepts (a) that word meaning (e.G., That 'fido' means fido) is irrelevant to logic and (b) that such sentences as 'all men are mortal' do not express quantified propositions but are about things (in this case, The class of men). If we note these confusions, And also that (b), Though not (a) has been abandoned by 'on denoting', We see what denoting is and how russell relates to frege on sinn and bedautung.