Members Tab
info
Once opened the object form, located inside the filter widget (i.e. over the tabs), there are more/less standard parameters - such as Code, Description, Creation Date, Last edit date - the ones you need to pay more attention to are Creation User, Editing User and to the optional parameter Linked Distribution List (the latter refers to the CRM list).
In this tab members can be added using the grid and there is no Object Widget that controls what the user inputed, except for the field Linked User; it will be inputed arbitrary by the user based of its necessities.