Series1.Marks.Style :=  smsSeriesTitle;
    // <-- Series1 , Series2, etc

Series1.Marks.Style :=  smsPointIndex;
    // <-- 1..2..3...  etc

Series1.Marks.Style :=  smsPercentRelative;
    // 100%..90%..120%...   
    // (% relative to previous point)