The third option, MARKERS, brings up the following sub-menu:
which facilitates placing and removal of markers wherever the user chooses. The marker symbol and color can be changed via option {TOP.CONFIG}NODES .
This permits placing of a marker by means of the cursor.
This permits placing of a marker by specifying its coordinates, in problem units, via the keyboard.
This permits erasure of all markers currently shown.
This permits the same general control over windowing as in
{TOP}DISPLAY described later. It is described in detail in
Section 
The INFO option permits viewing and changing of various node attributes, as detailed in the section on {TOP}INFO.