john carmack on "no clipping"

one time i asked john carmack about why he called static collision "clipping"/called the walk through walls cheat "no clipping" and heres what he said -@me_irl

From: @me_irl
To: johnc@idsoftware.com
Subject: Origin of term "no clipping"
Hey John,

I've been wondering, when you wrote Commander Keen, what inspired you
to call the cheat that turns collision detection off "no clipping
mode"? I'm used to "clipping" referring to culling/not drawing
elements which aren't visible to the user, so I don't understand this
usage of the term.

Thanks,
[@me_irl]

From: johnc@idsoftware.com
To: @me_irl
Subject: Re: [JC] Origin of term "no clipping"

I always considered it "clipping a movement vector", but you aren't alone in finding the terminology a bit off -- there are a couple game developers that still complain about that and some of my other terms today.