I have noticed that during time changes in the year they add a 10 to the symbol, for example: 7 would be 1007 and 8 would be 1008. I know that BN used to use this system in their day to not confuse the Empire Builders with Freight trains 7 & 8. But I have heard crews call it 1007 or 1008, not on daylight savings time and they cycle crews pretty often here so it wasn't habit from the BN days. I noticed that they stopped calling it 1007 or 1008 around 2016. I also have noticed crews calling trains 1004 and 1003 on SWC. Does anyone know why they stopped adding a 10 to the start of the symbol?