Long time ago when I was flying for the USAir commuter I was in Huntington WV when one of Business Express's Dash 8's pulled in. The N number was normally something like N123BEX. Someone, probably a mechanic, erased the edges of the B to make it look like an S. N123SEX is exactly how it looked. We KOFAO. Pointed it out to the crew that got off and they just kekd and said we know!!! They were proud of it!!!