Marking: the signs of pull-up pants on different brands are different, but generally they are marked with "front" or "back";

Plastic stickers: there are transparent plastic stickers on the front of the pants, but not on the back;

Blue tape: there are signs on the pants. The side with blue tape is the buttock, and the front is the side without it;

Size: Generally speaking, the side where the pants wrap around the buttocks will be larger than the front. After taking out the pants, spread them out and you can see the size difference.