I am curious. Did any informal (or even codified?) shorthands/abbreviations develop in the era of the telegraph to reduce character counts? Internet abbreviations were invented for convenience, ofc, mostly bc ppl r 2 lazy 2 type. But when messages were priced by length and also required a human to manually type out the code, brevity must have been an even more valued trait.
Are there survivng examples or glossaries or other evidence of telegraph shorthand?
They did indeed! One of the most widespread glossaries was William Clauson-Thue's A B C Universal Commercial Electric Telegraphic Code; this link goes to the 5th edition, published in 1901. A competitor was the Adams Cable Codex (this edition is from 1896). There were also codebooks for individual professions; one I know of offhand is the Theatrical Cipher Code, for use in the theatrical business and its ancillaries, though sadly I don't have a copy of that one.
These are less abbreviations and more code words, but they served much the same purpose - as you mentioned, avoiding both paying for long messages and also the transcription errors that might crop up in long messages. (To that last point, an 1881 article in Blackwood’s Magazine noted that BAD (-... .- -..) and DEAD (-.. . .- -..) are only different in the space before the E, which could lead to the grimly comical MOTHER WAS DEAD BUT NOW RECOVERED being recorded by the receiving operator. Even almost a century and a half ago, typos could have the strangest effects...)
George M Dodge's The Telegraph Instructor has a long glossary ( page 176) of railroad messages and outlines their rules. Aviation communications have their own syntax and vocabulary to make messages quick, clear and unambiguous, and railroads had their own for the same reasons. Trains ran under telegraphed orders, and with constant verification about arrival and departure. The local telegraph office was often logically located in the train station to both handle trains and to send messages for the public.
There were also merchants who would distribute catalogs with telegraph abbreviations to save money: a Ford dealer in 1917 could telegraph an order from the Ford Pricelist for a cylinder head cap screw with the word "cackle", and ask it be shipped by American Express with "topermolen". Thus, "Topermolen six Cackle ten Ambush one Barila for car 1,200,134" would be, "send by American Express six cylinder head cap screws, ten radius lock rod washers and one front axle assembly for car 1,200,134."