Nipple fetish indicates that not only are nipples present in the image, but that they are also a somewhat focal point of the image, typically due to them being interacted with in some fashion, or if attention is drawn to them in another manner.

This includes, but is not limited to actions such as licking (Nipple lick), pinching (Nipple pinch), pulling (Nipple pull), and sucking (Nipple suck).

Lactation may exist independently from the nipple fetish tag, and as such does not justify the tag on its own.