noun which may take the genitive case particle 'no', adverb
by the rules; according to the regulations
Used when something is done exactly as prescribed by rules, regulations, or established procedures.
規則通りに手続きを進めてください。
Please proceed with the procedure according to the rules.
彼は規則通りに罰せられた。
He was punished by the rules.
Compound of 規則 (rule) + 通り (as, in accordance with).