Absolutely. "Morse code operators" are a pretty broad constituency, but to pick a couple of instances there's a section in [The Telegraph Instructor] (http://www.morsetelegraphclub.org/library/files/html/dodge/dodge.htm) by G M Dodge on abbreviations with examples like "Tell t condr to set off 2 mt refrs at V to b iced" (Tell the conductor to set off two empty refrigerators at Valparaiso to be iced) and "Tbl on 42 seems to b in ur bd luk at t conctns & c if ty r art" (Trouble on wire No. 42 seems to be in your board; look at the connections and see if they are all right). In a slightly different context, military communications in World War II, the [Enigma General Procedure] (http://www.codesandciphers.org.uk/documents/egenproc/eniggnix.htm) has a section on Preparation of the Plain Text (the original message before it's enciphered on the Enigma machine), including "In order that the messages attain the brevity necessary for radio traffic, all abbreviations can be used which are customary in standard written German and in the Navy." As an additional complication, though, it forbids uniform abbreviation: "... it would be wrong always to abbreviate "Funkspruch" by "Fkspr.", because such regularities are an aid to unauthorized deciphering."

Broadening out slightly from pure morse code transmissions, telegraph messages were generally charged by the word rather than by the letter, so the focus was on reducing the number of words in a message rather than the letters per word; [How To Write Telegrams Properly] (http://www.telegraph-office.com/pages/telegram.html) has many tips on saving words, with an example of "extreme condensation practiced for example by foreign correspondents of the larger newspapers" (not to be attempted for the ordinary business or social telegram) where "The enemy has not yet been met or even seen on account of the entanglements thrown up during the night" becomes ""Enemy unmet unseen account entanglements upthrown night."

For greater compression still, a number of telegraphic code books were published in the 19th and early 20th century. Codes could be used to conceal the meaning of a message, such as the [Telegraphic Code, to Ensure Secresy in the Transmission of Telegrams] (https://books.google.co.uk/books?id=MJYBAAAAQAAJ&dq), but also to reduce the length of a message by replacing phrases with single words. In [The ABC Universal Commercial Electric Telegraphic Code] (https://archive.org/details/abcuniversalcom00clau), for example, "Illaurerei" means "You are putting me (us) to a great deal of inconvenience"; the code words also had a numeric value that could be enciphered if secrecy was also required.

Punctuation was generally skipped, so I'm not aware of any punctuation-style emoticons, but it seems there was a Western Union cipher code in which "73" represented "best regards" and "88" represented "love and kisses", which [survived into ham radio days] (https://books.google.co.uk/books?id=9tsDAAAAMBAJ&pg=PA286&dq=88+"love+and+kisses").