Spelling of disc

The earlier word is disk, which came into the English language in the middle of the 17th century. In the 19th century, disk became the conventional spelling for audio recordings made on a flat plate, such as the gramophone record. Early BBC technicians differentiated between disks (in-house transcription records) and discs (the colloquial term for commercial gramophone records, or what the BBC dubbed CGRs).^[1]

By the 20th century, the "k" spelling was more popular in the United States, while the "c" variant was preferred in the UK.^[2] In the 1950s, when the American company IBM pioneered the first hard disk drive storage devices, it used the "k" spelling. Consequently, in computer terminology today it is common for the "k" word to refer mainly to magnetic storage devices^[3] (particularly in British English, where the term disk is sometimes regarded as a contraction of diskette, a much later word and actually a diminutive of disk). Kodak's 1982 disc film used the -c variant. The RISC OS developed by the British Acorn Computers in 1987, and was subsequently forked when Acorn stopped working on it, uses the spelling 'disc' for magnetic media.

Some latter-day competitors to IBM prefer the c-spelling. In 1979, the Dutch company Philips, along with Sony, developed and trademarked the compact disc using the "c" spelling. The "c" spelling is now used consistently for optical media such as the compact disc and similar technologies.^[4]

The words disc and disk can appear frequently in medical journals and textbooks, especially those in ophthalmology and orthopedics, and thus style guides often foster consistency by giving rules for which contexts take which spelling. AMA style for this topic is used by many publications. AMA says, "For ophthalmologic terms, use disc (e.g., optic disc); for other anatomical terms, use disk (e.g., lumbar disk). In discussions related to computers, use disk (e.g., floppy disk, disk drive, diskette) (exceptions: compact disc, videodisc)."^[5]

Disc sports, or disc games, are a category of activities which involve throwing and/or catching a flying disc. Participants of disc sports consistently use the "c" spelling when describing the sports equipment used in these activities, which includes team sports such as ultimate or individual sports such as disc golf. This is a parallel to the spelling of "discus," the flat and round weight thrown in the track and field sport discus throw.