“Some say the mark began during a time when stories were submitted via telegraph, with “-30-” denoting “the end” in Morse code. Another theory suggests that the first telegraphed news story had 30 words.
“Others claim the “-30-” comes from a time when stories were written in longhand — X marked the end of a sentence, XX the end of a paragraph and XXX meant the end of a story. The Roman numerals XXX translate to 30.
“It is rumored that a letter to an East India company ended with “80,” a figure meaning “farewell” in Bengali. The symbol supposedly was misread, changed to 30 and took root.
“Some say the mark comes from the fact that press offices closed at 3 o’clock.
“And there’s the theory that 30 was the code for a telegraph operator who stayed at his post during a breaking news story until his death 30 hours later — versions of that story even include that the unfortunate operator hit two keys on his machine when he collapsed. Which ones? That’s right, 3 and 0.”
Read all the other theories here: So why not 29?