I have a question about the usage of the prepositions "on" and "under". Let's say the context is colleges with semester systems and quarter systems. From this website:
Of the 48 contiguous states, 40 state systems (83%) operate on a semester system and 5 state systems (10%) operate on a quarter system.
, which suggests that "on a quarter/semester system" is standard English, and that "under a quarter/semester system" is not.
But then, I saw this example sentence for the definition of "system" in some dictionary:
def 3a: Under the new system, students will have to pass an exam to graduate.
So, which one of "on a quarter/semester system" or "under a quarter/semester system" is standard English?