This is one of those "obvious in hindsight" tricks. The comma prefix gives you a namespace that's guaranteed to never collide with system binaries, shell builtins, or anything from a package manager.

I do something similar with my personal scripts — prefix them with a short namespace. The real win isn't just avoiding collisions though, it's tab completion. Type the prefix and tab, and you immediately see all your custom stuff without wading through hundreds of system commands.

The 2009 date on this is wild. Some of these simple unix conventions age better than most frameworks.