A simpler first check is to look at your itinerary. If you see different capital letters (booking class, also the first letter of your fare code in most cases), you know that you have a broken fare and can stop here. Otherwise, the itinerary is generally inconclusive (although deep discount fare codes are unlikely to permit stopovers) and you need to inspect the coding on the receipt or at least the fare rules to check whether your fare allows a stopover.