For CMS 7.19 I need to restrict content types in properties and I know that you can use the AllowedTypes attribute but with 7.5 this does not work with base classes (typically I need this to work with base classes), does anyone know of a workaround for this limitation?
Am not sure about if it can be done in the version you are using, but ...
Create an interface and put it on your content types that inherit from your base class. Create a UIDescriptor for the interface.
public class IPageFooterlUIDescriptor : UIDescriptor<IPageFooter>
this.DefaultView = CmsViewNames.OnPageEditView;
After you have done that you can use the interface in the AllowedTypes attribute.