Spotfire Ideas Portal
Similar to lines & curves in interface and implementation. Allow user to configure a region onto plot, i.e.:
Band - define upper/lower value for horizontal or vertical band
Box - define coordinates of corners
Polygon - dynamically add coordinates that would define a polygon, number of points would be flexible
Area between curves - say you want a coloured region between y = 2x and y = x
This would help identify data outside of an operating boundary, or help focus on data within/outside of normal region.