Canon PIXMA MG2440 - Manual (Page 51)

The favorite level can be specified in six levels. The more stars, the higher the
favorite level becomes.
Note
You can also register the favorite level by selecting an image then selecting
Favorite Level from the Image menu.
Important
When the file name of an image is changed or an image is moved, the registered
favorite level may be lost.
Even if you copy images with favorite levels set, the set favorite levels will not be
retained.
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