Soft enamel pins look like they were painted with plastic paint, and have very deep wells. Most of the Spanish and German pins fall into these last two categories. Rubber pins have never been tradable, and will not be under the new rules. Now, this isn't to say that you can't trade these pins with other visitors. As you can tell, there are a lot of great, desirable pins that don't meet the guidelines required to trade with CMs.
Guests can still trade anything they want with each other, so long as there is no money exchanged.
In addition to signs at the cash registers, Disneyland has designed a booklet for customers, explaining the policies and giving examples of good pin- trading etiquette. The booklet is also being translated into Spanish and Japanese, so that these visitors can understand the rules as well. A backstage display has been installed near costuming, to insure that all CMs learn about the new policies. Finally, expect to see a strong on-stage presence of Merchandise managers, to help explain the rules to the more stubborn guests. Customer reaction has been mixed.