Key legal question
Whether the filing should be treated as a public-law appeal rather than a abolished staatsrechtliche Beschwerde.
Extracted holding
The filing is to be treated as a public-law appeal because tax-liability decisions are not excluded under Art. 83 BGG.
Extracted reasoning
Under the BGG, the former staatsrechtliche Beschwerde no longer exists; in tax matters the public-law appeal is available unless expressly excluded.