Citing Legal Ethics Materials: There some rules in the Bluebook which are specific to the citation of legal ethics materials:
Rule 12.9.4 covers citation of Model Codes, Principles, Restatements, Standards, Sentencing Guidelines,and Uniform Acts. This rule is written for ABA model codes but can be used as a model for state ethics codes, e.g.,
N.Y. Rules of Prof'l Conduct R.1.1 cmt. 8 (2018).
Rule 12.9.5 covers citation of the ABA Code of Professional Responsibility and Opinions on Ethics. This rule is written for ABA codes and ethics opinions but can be used as a model for similar state materials (see T6 for abbreviations of institutional authors in citations), e.g.,
N.Y. Bar Ass'n Comm. on Prof'l Ethics, Op. 1182 (2020).
Rule 16.6.7 covers Proceedings, Regular Publications by Institutes, and ABA Section Reports.