In several locations, the Frisco used two letter-combination or truncated names to designate junctions, e.g. BV Jct = Blue Valley JA Jct = Johnston Ave KY Tower =Katy WS Jct= Willow Springs Dejun = Deepwater Junction, etc. At other locations, no abbreviations or truncations were used, e.g. Nichols Jct Southern Jct Pine Street Jct, etc However, I have always wondered about the particulars regarding Southern Junction and it's change to MK Jct. I never found an adequate explanation as to why the letters MK, until I looked through John Dill's 1907 List of Stations, and I noticed that the telegraph call for the tower at Southern Junction was "MK".