[rules-users] Deprecated Drools packages?

I keep seeing mentioned on the mailing list packages which have been deprecated (or are not part of the "stable" release), but I have not seen any javadocs or other documentation (and google has been no help) indicating *which* packages I should avoid using. Every time Eclipse gives me a choice between two packages for a Drools class, I am unsure which one to pick. Apologies if I've missed something obvious, but can someone educate me? Thanks! Mike