Rules for end-of-line hyphens? by u/Heavyduty35

Back in the heyday of typewriters in the office books like Dougherty's Instant Spelling Dictionary were kept on the desks of most typists and secretaries for looking up words for hyphenating. Standard dictionaries also provide this functionality, but obviously tend to be 10x the length and size and take longer to look up words, so for doing this at greater speed, these spelling books were common tools in the office.

See: https://archive.org/details/texts?tab=collection&query=instant+spelling+dictionary