Mid term tests and MLG

[Baconking]

DS is in year 12 studying 3 A-levels.

His school are reporting a MLG of C1, C1 and A3 after 1 or 2 tests, does anyone know what these mean?
My Google search brings up Cambridge English...he's not studying English.

I know it's early days but would be good to know how he's getting on from the school's perspective.

Thank you

It sounds like an internal school thing- if the report doesn't explain I'd contact the tutor or teachers directly?

I agree with PP that this sounds like your own school's grading system.

However ... does your DC not understand the results? Does he not know how he is doing and what areas he needs to improve in? At sixth form there is more emphasis in the students themselves taking responsibility for themselves.

(I'm skirting over how a school can come up with an meaningful MLG after one set of assessments at the start of Year 12 in any case)