I guess this is less of a regulation and more of an individual teacher. I had a math test that was multiple choice, with space in-between each question to do the work. I did everything correctly for a particular problem, including writing down the exact correct answer, but I circled the wrong multiple choice answer. There was a minus sign instead of a plus sign for one of the terms, and I just missed it.

When we got the tests back, and it was marked wrong, I asked the teacher if I could still get points for it because I clearly actually did the math right. The teacher said that only the multiple choice answer I circled mattered, so I still got points off.

The next test was 5 pages with 5-ish questions on each page. The front of the last page only had 1 question, so I wrongfully assumed that was the last problem on the test, but there were 3 problems on the back. I only noticed this when I went to turn it in, and with the teacher watching, I just circled 3 answers at random. It turns out, I somehow circled the correct answers, but the teacher marked them wrong because I didn't actually do the work; I just got lucky.

I complained, and to their credit, the teacher relented and gave me the points.