A mark of possibility is the semi-physical manifestation and empowerment of unrealized potential.

It is called a mark of possibility because there is a set amount of potential in each person, and a consequently finite amount of achievement that they can reach because of it. When that potential is high enough to be significant but too low to break through past the successes of others, you have the potential to gain a mark. It is something of a convoluted equation, and it is unclear why this is the case.

Only those with the potential to gain marks can see them. And, if you do not have a mark, you cannot describe one without looking at one.

In order to receive a mark, a marked being must arrive at a mutual consensus with you.

When a mark is received, it is dormant. You will be marked, but gain no other inherent benefit from it.

When someone that you know, that cannot see marks, manifests their own potential and gains success in life and begins to forget about you, your mark will become activated.

An activated mark will guide you to the abstract world. And once there, will awaken your full potential.