SCOTUS uses a distinct in-house citation style which, although it has a lot in common with the Bluebook, is not the same (differing in key places) and is as far as I know unique.
Is the citation style manual used in house for SCOTUS publicly available? Either because the Court has published it, or via FOI requests? It is probably possible to reverse engineer the citation rules from the Opinions of the Court, but do we have the guide for it?