Key legal question
Whether the cantonal appeal had to be treated as a federal administrative law appeal rather than a state constitutional complaint
Extracted holding
The case concerned the implementation of binding federal tax-harmonization law, so review under Art. 73 StHG was available and the constitutional complaint was treated as such.
Extracted reasoning
Art. 69 StHG applied from 1999 in cantons that changed assessment systems then; Zurich had no room to deviate. The dispute was therefore about the cantonal implementation of federal law.