As described here : http://www.dnnsoftware.com/answers/view-edit-profi...
DNN currently has a visibility option for profile properties, however I would like to see these to be extended so that profile properties can be assigned to "user defined" visibility options OR the ability to allocate a role to the visibility for profile properties.
Buyer Members and Seller Members exist in a DNN website Buyers are given the custom role "Buyers", Sellers are given the role of "Sellers".
Out of 20 profile properties 10 could be defined as common for both roles (or all members) 5 could be viewable/editable buy a Buyer role only and the remaining 5 could be viewable/editable buy a seller role only.
This could go a step further and allow different registration forms based on the above as a future enhancement, but not as important as the above.
This makes DNN far more powerful for use on member based websites.