The purpose of the example here is to design a keypad. The function of Masks-Include/Excludecan be applied to only display the specific keypad area and to exclude the region that you don't want.

First, design a density profile, and select the Mask/Masks-Include/Exclude in toolbar. Define the position and size of mask and insert the keypad image. 

In the column of "Reverse mask in mask", "False" means to exhibit the pattern of mask only, and "True" means to exclude the pattern of mask itself.