A race course is record eligible if:
1. measured by a World Athletics approved measurer
2. The elevation change from start to finish does not exceed 1m/km
3. The straight line distance (separation) from start to finish does not exceed 50% of the total distance. New York, Chicago, London, Berlin & Tokyo are all record eligible. Many people think that the NY Marathon is not but the separation is just under the allowable at 48%