You might wanna read the main superpowers page first!
Bauhinia, being the bureaucratic fanatic it is, have a system of identifying and cataloging people with superpowers (called "the gifted").
Each power has a level scale used to measure how strong a person is at that power. They start at 1 (0 meaning "no power" which is always omitted except in specific settings) and have no upper bound.
A person's power level would change, usually increasing when they're growing up and decreasing when they're growing old. You know, like most normal human body functions.
Each year during the health examination carried out at schools, the respective hospitals carrying out the exam will do extra tests on the gifted to determine their power level and update records accordingly. As an adult, you can go test if you want, but usually the power level of an adult stays around the same anyways.
The testing and the determination of levels can be quite subjective sometimes, especially for stuff like mind reading. And when a person's level gets too high, a precise number becomes meaningless.
On the info section of each character page, you can see their power listed if they have one; and if they're Bauhinian and have taken a test, the level would also be written there. Otherwise it would be "unregistered."
The definition of superstrength is pretty muddy. If really strong people in real life got transported into the world of TIR, would they be registered as having superstrength? Yeah, probably. Regardless, the Bauhinian government marks children who look strong enough for their age down as having superstrength.
Testing is just lifting weights. The heavier you can lift, the higher your level. The Bauhinian government is responsible for any injury sustained during these tests (that is, if you can prove the test is administered by the government), so the doctors don't encourage people to try out heavy weights, making a lot of the levels lower than they actually are. Also, people can fake a lower level too.
The examiner would think of something, and ask the examinee to describe it. Levels determined on the accuracy of the description.
Immortality does not have levels and is registered when they pop up in DNA tests. Unless the parents are from some rural area and didn't do one properly, or their hospital didn't report it. Even then, people would know you're immortal when you reach something like 120 years old anyways.
Magic is the most subjective out of them all. Like, how are you going to make a level system out of stuff like telekinesis and teleportation? If someone is good at telekinsis but bad at teleportation, but another guy has it the other way around, who would be higher and who lower?
Bauhinian bureaucracy has an answer. It's easy. Just list telekinesis as the "default" form of magic and mark everyone according to how good they are at lifting things into the air. We can even use the same gym as the superstrength guys! Isn't it genius?