Despite the availability of XML files and the code generated, sometimes external “plug-ins” to the objects are also to be written (such a plug-in would use the status system). Elements allows the compilation of classes, which can extend the query to an object, its properties, add more columns to the list or more fields to the form. They can also take part in the data validation process or add actions to the object (e.g. the system which archives the records adds the actions Archive and Un-archive). Extensions are also registered at system level and are subject to access control.