In reference to the aviation industry (and getting off track of this thread) the reason for acronyms was time and space - time to communicate everything on radio when other people are wanting to do the same, and space to write down the large amount of information, whether it be on a flight plan or a flight strip at an airways operations unit. A lot of it goes back to the morse telegraph days, be it for shipping, railways or telegraph. The NSW railways like most others had a string of standard letter groups which meant standard information such as how many tarpaulins are at your depot; how many open wagons do you have; the toilets in a particular carriage aren't working, etc. etc.
Then there are the locations - ASDU was Dubbo because It was (a) located in Australia (b) in NSW and (c) its two letter designator DU showed that there was an airways operations unit located there - I worked in it for 16 years. Whereas Bathurst was BTH with a three letter abbreviation because there was no Airways Operations Unit located there but it was a flight plan location.
But if you use acronyms without explanation, then you could be subjected to the Q code symbol QBL - Are you flying in cloud? In other words, come down to earth, mate.
Therefore, perhaps if we could have the acronyms with a short explanation for those who are not familiar with the geography and terminology associated with the story being told. Otherwise you have pulled the air on us mere mortals who have not had the pleasure of wielding a banjo.
Many of the acronyms are not broad based, there is a word, Broad that for some with neat and small writing hand would log that as their depot, and that made sense, some even tried to tier the name Broadmeadow within the small box of the log book. Each branch had their own acronyms for advising various events, happenings, warnings and many other areas that were relevant to their own branch but some were cross branch ones as well.
Things such as AMBA, is for traffic, mechanical. Signals, per way branches, and is a forecast list of trains that are scheduled within a set time frame, usually there are 3 per day, that made the Mechanical branch and the roster clerks provide the crews for those trains, likewise the Traffic branch would work with the engine and train controllers to provide the locomotives, guards and the projected loading for those trains, if no engines were available, or crew, guard or loading, the train would be Amexed to all relevant areas, and that included signal boxes, stations, depots and the like.
It was interesting to me to sit in signal boxes one was Tumulla where down trains were all pretty much banked up the grade, at around 0900 each morning the West train control would provide a bell code for the departmental phone line and all signalmen/Station Masters between the relevant area, Lithgow - Orange would pick up the phone and listen in, pen in hand ready to take the program down on the train running book, after a brief pause all the staff would respond to the request that they were on line as the controller called out the box/stations in order, those in the locations answered by their locations name in order.
When all was set, the control officer read out the down and up trains for the afternoon night shift working, a D was written in for some trains that had double headers on them some had a D for Diesel, this was vital in early transition days as the staff had to be carried on the 2nd engine in a double, as that was the train engine, the front one was the assistant. A double diesel caused issues as there was only a crew on the front engine, in MU working and the signalman would only be ready to exchange the staff with the 2nd engine, it caused a general rule change that no matter what type of engine/s or train the staff was to be taken and held by the front engine.
When a train was Amexed, the signal box train book would put a big long tailed C around the amexed train with a meaning of Cancelled.
There were so many of those acronyms that it was funny, I remember some but thankfully so many have been lost in time for me.