About Setting Visibility of the Pick List Object Definition

Developers can override the visibility set at the business component level by setting a different visibility type on the Pick List object definition, in the Visibility Type property. When you do this, you override the visibility set at the business component level in a specific instance of that business component for all users of that instance.

For example, you might want partners to be able to add new fund requests and associate those fund requests with campaigns in which they participate. However, you want partners to see only campaigns to which they have access. You can configure a special picklist for this use, and set the visibility on that picklist to Sales Rep, so that partners can only select from accessible campaigns when associating to a fund request.