Sel_Action userexit at each mask.
The userexit internally calls the function iwf_edt_lis (edit record).
In browser lists the userexit has a special meaning. Then it can get the parameter defined for the function iwf_brw_ent at the Sel_Action trigger. This installs the DataView default behaviour into the browser. After a click or double-click on an element in the browser, the mask specified in the parameter string will open.