The phrase "a code under which" is correct and usable in written English.
It can be used to refer to a specific set of rules or regulations that govern a particular situation or context.
Example: "The organization operates under a code under which all members must adhere to ethical standards."
Alternatives: "a code that governs" or "a code by which".
A philosophy and a moral code - under which circumstances is it permissible not to tip one's "titfer-tat" at a lady?
This is how we got a tax code under which Warren Buffett pays a lower tax rate than his secretary.
In a sign of more demanding times, the pensions industry is about to adopt a new code, under which pension-fund trustees will get a detailed report every six months on fund managers' investment procedures, as well as a meticulous break-down of the costs of managing a pension-fund account.
"Everyone turned a blind eye," says one Socialist who knows him well, "because he was a dream candidate".On the left in particular, there seems to be a prevailing code under which to refuse sexual advances, even when unwelcome, is somehow bourgeois.
Third, they introduce an explicit code under which individuals' obligations to each other vary with their relationship.
The efforts of these groups, particularly 527s, which are named for a section of the tax code under which they fall, worry campaign finance watchdogs because many can take unlimited contributions from donors and have limited oversight.
Environmentalists said Rousseff's pledge to restore 120,000 square kilometers of forest amounted to half that achievable by simply adhering to Brazil's contentious 2012 Forestry Code — under which a 210,000 square kilometer target had already been slashed from 500,000. .
The new benefit would be part of a sweeping change in the tax code under which employer-provided health insurance, which is how more than half of Americans get their coverage, would be treated as taxable income.
It subsequently emerged that the hotel's new owner, the Sultan of Brunei, was implementing a new sharia law-based penal code under which homosexual acts would be punishable by stoning.
