Haha I've never heard of this but lucky i went with 18

I'm equally laughing because I remember a coding snafu I ran into once, where we were aggressively filtering out "1488" turns out someone finally joined and "1488" was part of their user ID (auto-increment field!), and we realized maybe we shouldn't be checking the auto-increment field, not sure if it was me being too aggressive and not thinking about it, or another developer, but I did laugh once I figured out why that one user was unable to use half of the web app. This was for a gaming community based project, we had a lot of trolls come and go, and they would definitely shove these sorts of references in their usernames, and anywhere else you had custom user input.

The internet is a magical place.