Library Hand, the Fastidiously Neat Penmanship Style Made for Card Catalogs

AtlasObscura:

“Dewey and his crew of “a dozen catalogers and librarians” spent, in his estimation, “an hour daily for nearly an entire week” hashing out the rules of library hand. They started by examining hundreds of card catalogs, looking for penmanship problems and coming up with ways to solve them. They concluded that the “simpler and fewer the lines the better,” and decided that, while a slant was best avoided, a slight backward slant was acceptable. Then they got to the more nitty-gritty stuff, such as whether to opt for a “square-topped 3” or a “rounded-top 3.” (The rounded-top 3 won out, as it is less likely to be mistaken for a 5 during hasty reading.)”