Would QLA include any airports in addition to LAX, ONT, SNA, BUR, and LGB, like PSP? Or perhaps excluding LGB?

What is the most widely cast city code? Mapquest says BWI is 56.4 miles from IAD (though I'm told BWI isn't part of WAS in some systems), and ONT-LAX is 56.7 miles. EWR-HPN is a mere 47.4. But surely LON has them all beat.