According to SEO Perth Experts, a post that wins the prize for the most technically detailed SEO advice ever is this one; Search Engine Land shares these discoveries about punctuation quirks.

Honestly never heard of most of these. Dashes vs. underscores, pipe characters, using only lowercase… How did it take this long to be discovered?

To explain about the underscores part regarding “Google was written for nerds by nerds” – Computers have always had a problem with the space character in the name of anything, because the space is how we tell the computer that a new name is starting. This is especially a problem in the early days of computing, in programming languages, and general file system tinkering. So there evolved work-arounds to keep it human-readable: One of them was called “camel case” where you write all one word using interspersed capitals (WordWideWeb), another was alternating upper-and-lower case (worldWIDEweb), one was using underscores for spaces (world_wide_web) and so on. Underscores became the dominant convention, so you’d want to avoid underscores unless you want them taken literally. Now memorize all that and bewilder your bar mates with this trivia!