Demo Disk unused content FAQ

I'll be looking through unused content on demo disks, primarily Euro Demo.
Why? Because demos can be of earlier builds, and will likely have more unused content, like placeholder stuff, debug stuff, etc.
And also I have the notes handy for when I compare them to the retail versions.
I'll be looking at the Euro Demos that I played growing up, in order (including Euro Demo 49, which I never got for some reason).
I just thought I'd make this in case someone wonders why I'll be posting demo disk pastes.