A player can be affected by a maximum of 12 quiz medals.

Currently, you can't get more quiz medals in quiz if you already have 12.
You can't get beyond this limit with categorizing either.
You can't bid in auction on quiz medals once you reached this limit.
If, somehow, you still get more, only 12 will take effect. The medal's description was wrong, it did not show this, unfortunately, now we corrected it.