As an example of duplicate airspace waypoints ("fixes"): Head over to <a href="https://opennav.com/" rel="nofollow noreferrer">https://opennav.com/</a>, and search "PINTO". You'll find the identifier being used for a waypoint in the United States, in Columbia, and in Chile.<p>In general: waypoints are five letters, VORs & similar are three letters, and NDBs are two or three letters.<p>This is an example of how older forms of identification come under stress in a modern world. It never mattered if you had a duplicate-named waypoint many countries away away; waypoints were defined by intersecting lines (typically relative to two VORs), or by a set distance from a reference point (such as a VOR/DME). Plotting a route would make it obvious how the different waypoints fit in, relative to the start/end and intermediate navigational aids (VORs etc.).<p>But then waypoints started getting GPS coördinates, and were collected into large databases. It's a problem that has been known since it became a problem, but it still causes issues (like leap seconds!).