flanker means: Modifications made by a manufacturer to an existing product, such as blue MMs. (in Cooking Dictionary)

What else does flanker mean?

A soldier who flanks, particularly one that is so placed as to guard the flank of the column of marching troops. (in Merlin Dictionary)

A line of extension products, like a diet soft drink or liquid detergent, can be added to the main product to increase sales. (in Merlin Dictionary)