Originally Posted by
docbert
So you'll have United 3541 for the first flight, and United 3541 Tango (or other codes, but tango seems the most common) for the second flight.
If I recall correctly, there are only a handful (maybe 5?) of "valid" suffixes -- (T)ango being popular, but I think (K)ilo and (R)omeo are also in that pool.
I think I was told it has to do with ease of reading/differentiation on radar screens (not being confused with a number, like say (I)ndia could be)
Change of Gauge flying is so much fun