Custom Field Types
Applies to: SharePoint Foundation 2010
As you store your business information in SharePoint Foundation, you may encounter instances where your important business data does not conform to the field types included in SharePoint Foundation, or situations where you want to further customize those general field types. SharePoint Foundation enables you to create custom field types. These custom fields can include custom data validation and custom field rendering. You can also customize the way that variable properties of your custom field types are processed and rendered when users set property variables and create new columns that are based on your custom field type.