OScope__EnableMarkers (ul_pbar_graphics)

 *  Synopsis:
 *    #include <ul_pbar_graphics:oscope.h>
 *
 *    TOScope__Result OScope__EnableMarkers( void )
 *
 *  Function intent:
 *    OScope__EnableMarkers() <.zzzzzzzz.>.
 *  Function parameters:
 *    none
 *  Function return value:
 *    CBS_OK    success
 *    ~CBS_OK   OScope__DisplayScreen() already called