This device includes wettable flanks for at least one package. See the Features section on the front page of the data sheet for which packages include this feature.

Wettable flanks help improve side wetting after soldering which makes QFN packages easier to inspect with automatic optical inspection (AOI). A wettable flank can be dimpled or step-cut to provide additional surface area for solder adhesion which assists in reliably creating a side fillet as shown in Figure 8-2. Please see the mechanical drawing for additional details.