Modifies the current display by including the specified field or
  class in the display.  The ADD command can also be used to include
  the following in the display: circuits that are in a particular state,
  connections that are in a particular state or of a particular name, or
  systems of a particular node name, system ID, or hardware type.

  Format:  ADD class[,...] [/qualifier...] [field[,...]] [/qualifier...]

  Examples: ADD CIRCUITS,CONNECTIONS,LOC_CONID,REM_CONID
            ADD CIRCUITS/TYPE=ALL, CONNECTIONS/TYPE=NOOPEN