This doc has often talked about "claiming" or "marking." Claiming is typically done by way of biting your partner on the neck, stimulating their scent glands. This normally happens during sex - often during a heat or rut - and it's a very intimate gesture. It wouldn't be shared by, say, an alpha and an omega who started dating a week ago. Once a mark has been formed, we say that the pair is "mated." Bonds/claims can be broken, but it's not easy, and will be very emotionally taxing for both parties.

Bonding bites/claiming marks usually require multiple bites over time to make the mark last. It signals to other people that this person already has a pack or a mate.

Mating bites are on the neck
Pack bites are anywhere else, arms are a common place.

Biting also plays a large role in other parts of the omegaverse - dominant types can place warning bites on the neck if their partner or submissive is not submitting. Alphas can bite alphas in fights - again, typically used as a "dominance" gesture. During sex, people will bite themselves or bite non-neck areas of their partners to alleviate the need to bite if it gets intense or feral enough.