Questione giuridica chiave
Whether the federal appeal against the cantonal remand decision is admissible despite its incidental nature.
Decisione estratta
Yes, because the remand order causes irreparable harm to the tax authority by binding it on substantive instructions.
Motivazione estratta
A remand decision is ordinarily incidental, but here the authority would be unable to challenge the final decision later on the substance already fixed by the appellate court.