に則(のっと)ってAccording to, In accordance with, Based on, In line with

に則(のっと)って is a formal expression used when something is being done 'according to (A)', or 'in line with (A)'. This is usually some basis, foundation, or standard which has a long running history. The case-marking particle に is being combined with the て-form of the う-Verb 則(のっと)る 'to follow along with' in this grammar pattern. Based on this, the literal meaning is just that (B) is something that follows along with (A).

While several forms may be seen, the most common are a noun followed by にのっとって, or a noun followed by にのっとった which will then modify a second noun.

Both the kanji form and the plain hiragana form are quite common, so it will be helpful to remember both.

As (A) is generally considered to be something that has some kind of foundation. It will mostly represent a thing that has some kind of inception point from which point little, if anything, changed. Some examples are laws, traditions, standards, codes of conduct, etc.