We had bands and sets when I was at school.
Each band had 5 sets within it and there were 2 bands. So Band 1 had sets 1/2/3/4/5 and Band 2 had sets 1/2/3/4/5. Band 1 were academically strong. Band 1, set 1 were clever clogs and less so down the bands and sets. So for each subject we were 'band something, set something'. Everyone was in the same band for all subjects, and most people were in the same set for everything too but a few people were a set higher or lower for a couple of subjects.
There used to be a really good reason for being in lower sets....
I was in band 1 set 1 and band 1 set 2 for everything except Maths for which I was in Band 1 set 3. At the time Maths was tiered so you either did Higher, Intermediate or Foundation. If you were in Band 1 set 1 and 2, then you had to sit the Higher paper - you had no choice, the the rest of band 1 sat Intermediate and band 2 sat Foundation. The highest you could get in Higher was A, Inter B and Lower C and the marks you needed for a B were less on Inter than Higher and the marks you needed for a C were less on Foundation than Inter.
I was never going to get an A so I wanted a B. It was easier to get a B on the Inter paper than the Higher paper and the certificate didn't say which paper you sat.
You couldn't request to be moved up or down sets or bands - it was all based on your performance. So I started handing in terrible homework and classwork whilst in band 1 set 2 (Higher paper class) until I was asked if I'd feel better in a lower set. I got moved to a lower set on the basis that I found higher maths difficult (not a complete lie) and sat the Intermediate paper. Got my B at GCSE. Tactical set moving FTW. There were people in band 1 set 1 and 2 who didn't get an A on the Higher paper and they had to get more marks for their B than I did for my B.
I don't think you can do tactical set moving anymore since all the papers are the same now, but if you can I highly (or should that be intermediately) recommend it.