Known Unicode Encodings
The list of known Unicode encodings is identical to the one found in a consuming project for C++ called ztd.text. That list can be found here.
The known Unicode encodings are important because they are evaluated before all other candidates as an intermediate in the service of performing an indirect encoding conversion; not every Unicode encoding is given such an elevated status, though. Only the encodings listed on the indirect conversion desing documentation are given the elevated encoding status and checked before all else: otherwise, the order of finding and the priority of picking such an indirect conversion is unspecified. A stronger guarantee can be made by using the select-based functions when opening a cuneicode conversion routine in the registry.