old system; old order
General term for a previous system or regime, often contrasted with 新制 (new system).
See also: 新制
Some of the old-system laws are still partially applied.
prewar education system; pre-World War II education system
Specifically refers to the Japanese education system before the post-WWII reforms; often used in contexts like 旧制高校 (old-system high school) or 旧制大学 (old-system university).
See also: 新制
My grandfather is from the last generation that graduated from the old-system high school.
The education system changed from the old system to the new one due to the school reform.