Brevity, Brevity.

The folks who use "hashtags" tend to steer their message - sometimes tartly - using very few words. In the early and mid-twentieth century much communication was transacted using telex, teletype and wireless. All our vessel dispatches went via Western Union or RCA radio and we also tended to keep them terse. You see, Western Union had a pricing structure wherein ten words or less was one rate and the scale graduated for additional words.  My mother was in the work force circa 1915 and she had an eight block walk to her office in Kensington. One winter they had a severe blizzard and she was prevented from getting to work. But one brave fellow made it in and in a self serving manner he wanted to impress his superiors. The switchboard was down so there was no phone service. So our apple polishing friend sent the following telegram via Western Union to his boss "IN THOUGH SICK, FEW OTHERS HERE." Brevity, brevity!
tjs