For the terminally curious, Apple has a knowledgebase article: What’s the difference between a “disc” and a “disk”?
Short story: Discs are optical, disks are magnetic. But you knew that already, right? And:
Although both discs and disks are circular, disks are usually sealed inside a metal or plastic casing (often, a disk and its enclosing mechanism are collectively known as a “hard drive”).
Absent from the article is any mention of how it came to pass that Apple gets to speak so authoritatively on the subject. Granted, this seems to be standard tech lore, but it’s weird to see the KB regarding itself as if a dictionary.
Music: Duke Ellington & John Coltrane :: In A Sentimental Mood
I’m ashamed to admit I did know that already. Being a MiniDisc fan, I believe that the article could be even more specific. It seems to be the technology of the reading phase of a media has traditionally assigned the spelling in question. MiniDiscs and other magneto-optical (MO) formats are written to by a combination of heating a substrate within the disc and then “flipping bits” magnetically to encode data. Reading is entirely in the optical domain.
For the truly geeky, there’s this Wikipedia entry on the subject.
That’s exactly the way we did it at Mobile magazine… was even written into our style guide, as I suspect it is in many magazines. It’s common usage — but, I still think it’s crazy!
%DISCNUMBER% is win