Theory and experimental practice in the field of soft x‐ray emission from metallic solids are briefly reviewed, and measurements on a number of systems (Al, Al in AuAl2, Al and Mg in Al‐Mg, Cu, Cu and Ni in Cu‐Ni, Li, Mg, Na, and Ni) are critically evaluated and compared with the results of other techniques and theory, with a view to establishing the pertinence of the soft x‐ray measurements and indicating specific guidelines for enhancing their value.