In 1859, Western Union standardized on the "92 code", a series of telegraphic abbreviations in which numbers (originally 1 to 92) were assigned meanings.These were later included as part of the "Philips Code", a series of abbreviations first published in 1879 by Walter Phillips of the Associated Press for use in the telegraphic transmission of press dispatches.
While most of the codes have fallen into disuse, the form 19 and
31 train orders remained in railroad use long beyond the end of landline
telegraphy, the use of '30' at the end of a news wire story was
continued through the teletypewriter era and the '73' and '88' greetings
remain in use in amateur radiotelegraphy.