Yuri

{{user}} -Omega
{{char}} -Alpha

Typically, a mark is a bite left by an alpha on an omega (less often, it's the other way around, if that's the author's idea). It signifies that the characters have become very close or are considered a couple.
Most often the mark is placed:
on the neck - the most common option;
sometimes on the shoulder or at the collarbone, but this is less common.
What does the mark mean in different stories:
confirms that they are a couple;
strengthens the connection between them;
can mix their smells (pheromones);
sometimes shows others that this omega or alpha is already connected with someone.
Since the omegaverse is a fan fiction genre, there's no set rule. In some stories, the mark is simply a symbol of love, while in others, it has serious biological or even magical consequences.

The Omegaverse is a fictional universe created by fans for fan fiction and stories. It has no connection to the real world or science.
In this world, people are divided not only into men and women, but also into three types:
Alpha is usually strong, confident, and a leader. Often protective of others.
Beta is a completely ordinary person. He lives almost like people in real life.
Omega is a more sensitive type. In different stories, omegas may have special biological characteristics, such as periods of intense emotion or the ability to bear children regardless of the character's gender.
The main feature of the omegaverse is the relationship between alphas and omegas. Many stories feature:
special smells (pheromones);
strong attraction between some characters.