To edit multiple receptacles at one time, go to
DM Electrical 
Receptacles Edit Multiple Receptacles.
Design Master take you to the drawing and will ask you to Select Objects. Select the receptacles you wish to edit. The Edit Multiple Receptacles dialog box will open as shown below.
Active check boxes indicate which definitions may be edited for the chosen receptacles. To indicate that you wish to edit a certain field, check the active check box as shown below.
Then, to indicate that you wish to have a subscript note appear, check the second active check box and type the desired note in the blank and active typing window as shown below.
Follow this same procedure for any of the active check boxes in the Edit Multiple Receptacles dialog box that you wish to edit, then press OK. Design Master will have save the changes in the database and have made the changes in the drawing.