Gets or sets an array of 2 or 3 System.Drawing.PointF structures specifying a callout line attached to the free text annotation. 3 points represent the starting coordinates, the knee point, and the ending coordinates of the line. 2 points represent the starting and ending coordinates of the line. The coordinates are in default user space relative to the upper left corner of the page's media box, with the Y (vertical) coordinates increasing from top to bottom.

'Declaration
 
Public Property CalloutLine As System.Collections.Generic.IReadOnlyList(Of PointF)

public System.Collections.Generic.IReadOnlyList<PointF> CalloutLine {get; set;}