noun, noun or participle which takes 'suru', transitive verb
adoption; following (a precedent, custom, etc.)
Refers to taking over and using an existing method, system, or practice, often in formal or institutional contexts. Can be used as a noun or as a suru-verb.
新制度は旧制度を襲用したものだ。
The new system is an adoption of the old one.
This rule follows the precedent.