Though Selection Lists are initially created by GeneXus, they may be modified like any work/web/SD panel. Once this happens, GeneXus is no longer in charge of it, so it will not be updated when the associated table is modified (as opposed to what occurs with default lists).
If at a given time you regret having assumed a selection list, you may delete it so that in the following specification of a transaction/WWSD using it, it will be created again automatically and return under GeneXus control again.
It is possible to modify the form/layout, add events, etc., ensuring that the ‘Enter’ event in Web/Win, or the ‘Select’ in SD, maintains its feature of returning, in the output parameter, the value selected by the user.
Upon the need to receive and/or return more parameters in a selection list, in addition to redefining its parm rule, we need to use the prompt rule to invoke it explicitly from the objects that need it, with the new parameters.