Constitutionally, organizations in both the functional and territorial systems of governance are assigned to a system of ranks. Central ministries are at the same rank as provincial governments. Writes Lieberthal, "One key rule of the Chinese system is that units of the same rank cannot issue binding orders to each other. Operationally, this means that no ministry can issue a binding order to a province." This means a province may challenge, overrule, or ignore decisions made by a ministry. This two-dimensional arrangement sometimes creates undesirable conflicts, and there have been calls for tiao-kuai integration (), although this is unlikely to occur due to resistance from the provinces.