Note the footnote at the very bottom of the page: "This article is based in part on the Jargon File, which is in the public domain."
The Jargon file is reaaally old, back when the very large majority of people had no idea what a computer even was (late 70s to early 80s). So it might seem like common knowledge now, but it probably wasn't even common practice back then.
Of course, why they decided to make that into a wikipedia page, I have no idea. I think some editors enjoy actively seek out the most obscure or mundane topics they can think of in order to create pages for them.
