I’m also a university student, and I created a separate system within my system. I found I naturally organized classes based on semester and where they were in my schedule, so I came up with this:
SX.C.ID
ex S5.4.07 is ID 7 of class #4 of semester 5.
The S separates it from the main structure I have to keep track of records, media, and the like. As a result I only have 3 areas, but it’s enough for what I need.
If you’re going for minimalism, maybe drop the first dot? I experimented with C21.07 - ID 7 of class 21 (or even semester 2 class 1), but personally found the visual separation between semester and class helpful.
I might make a full post going in detail, but that’s the basics. JD for University - SX.C.ID
Hope that helps!