We discuss how local moment physics is modified by the presence of interactions in the conduction sea. Interactions in the conduction sea are shown to open up new symmetry channels for the exchange of spin with the localized moment. We illustrate this conclusion in the strong-coupling limit by carrying out a Schrieffer Wolff transformation for a local moment in an interacting electron sea, and show that these corrections become very severe in the approach to a Mott transition. As an example, we show how the Zhang Rice reduction of a two-band model is modified by these new effects.

Latex file with two postscript figures. Revised version, with more fully detailed calculations