Current migrating from Vite

Create a [[...slug]] directory in your app directory.
Since in this guide we're aiming first to set up our Next.js as an SPA (Single Page Application), you need your page entrypoint to catch all possible routes of your application. For that, create a new [[...slug]] directory in your app directory.

What is supposed to be the name of the directory? I can't mkdir or cd into a directory called [[...slug]] on linux.