Hello Nathan,

I've been working on a solution for you. I updated the sample our team provided to you previously to include another line with the same string title and added some checking in place for any duplicate titles and set that item's LegendItemVisibility property to Collapsed. The following code can be added in DataChartLine.cs.

  foreach (Series series in chart.Series)           
  {               
      if (series is ScatterLineSeries)               
     {                   
          if (title == series.Title as string)         
          {      
                   scatterLine.LegendItemVisibility = Infragistics.Portable.Components.UI.Visibility.Collapsed;                
                   break;             
          }  
      }             
  }

Let me know if you have any questions regarding this matter.