See Ctein's Post Exposure for a section on RC print permanence. After 2 years he found extensive silvering-out (oxidation) and bronzing in both Agfa and Kodak papers when untreated, especially when under acrylic in a frame and on display in normal room light. He found that treatment with Sistan, light selenium toning, or both, improved print life greatly. There's a bit more to it than this brief summary. He describes the changes in RC paper over time, baryta bases, and discusses his ongoing tests with treated prints in different storage conditions, begun in 1995. The book is copyright 2000, so includes more recent materials. In my estimation, it's worth buying for this and many other reasons.
Originally Posted by DannL
I've had better luck than Ctein with RC prints, but not with all of them, and I'd take his advice on treatment for anything I wanted to live as long as possible.