The criteria for redrawing are not only respect for equal voting power stricto sensu through the design of constituencies with a similar number of inhabitants, resident nationals or registered voters per seat. In majority or plurality systems, gerrymandering has to be prevented and it is therefore suitable that legislation provide for rules intended at avoiding such manipulation (even if they cannot prevent it completely by themselves), such as the requirements of contiguity in the shape of constituencies and of respect of administrative boundaries. For example, Hungary specifies that constituencies cannot cross county boundaries nor the boundaries of Budapest; constituencies must form contiguous areas. In Iceland too, constituencies should form a contiguous whole as much as possible. In Ireland, a breach of county boundaries should be avoided, constituencies will be contiguous and there will be regard to geographic considerations. These principles are reflected in the Code of Good practice in Electoral Matters.