This chapter discusses surface core-level shift data for metals. Changes of the W(110) 4f7/2 spectra with polarization and contamination is illustrated. Analysis of the W 4f7/2 photoemission spectrum of a clean W(110) surface and a scan encompassing the W 4f5/2 and 4f7/2 components are presented. The important phenomena at the surface are the changes in the natural width and the conduction-electron screening. These conclusions depart from all previous interpretations of surface-atom corelevel spectra and are not limited to W(110). Experimental phonon widths versus temperature of the bulk and (110) surface W 4f7/2 levels compared with the results of two theoretical calculations are presented.