It’s Eugene Volokh, The Law of Pseudonymous Litigation, 73 Hastings L.J. 1353 (2022); I hope it’s a useful resource for judges, lawyers, professors, students, and even pro se litigants.
I’ve tried to make it both analytical (setting forth in detail the key policy arguments and the key internal doctrinal structures) and descriptive (citing decisions from courts, especially but not only federal courts, all over the country). It’s not particularly normative: I don’t offer a bottom line as to when pseudonymity should be allowed and when it shouldn’t be. But in my experience, the analytical and descriptive often tends to be more practically useful than the normative, plus I really am torn about the normative in many ways here.