Residential status determined by physical presence and income-linked tests under income-tax law to classify ordinary residency. Determination follows a two-step test: Step 1 classifies an individual as resident or non-resident based on prescribed physical presence thresholds in the relevant year or in combination with presence in preceding years, subject to nationality-origin concessions and an income-linked modification with a deeming condition for certain citizens. Step 2 applies only to residents and classifies them as resident and ordinarily resident or resident but not ordinarily resident by reference to historical non-residence or cumulative presence tests, including recent amendments creating additional not-ordinarily-resident circumstances.