The Panel Maintenance is located at shortcut /PANELS or at menu =A.SS.D.M.P, the "MODS : Panel Maintenance Menu". Here you can list panels from one of the libraries which are specified in DD-Card /PANELS of the Netmaster Job. The delivered Library PANLDIS is read-only and cannot be edited. If you want to edit a panle of PANLDIS then copy the desired panel into PANUSR (or any user-defined Panel Library) and edit it there.