OK, so they're not really secret, and they've been around for ages, but Netflix's "genre ID codes" are internal codes the streaming giant uses internally to organize its library into thousands of hyper-specific genre categories and combinations. It's actually a leftover from its DVD-by-mail rental days.

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. (NEXSTAR) – Some people love a good action flick, while others go crazy for horror. But what about ...