Q. Editing an anthology of academic nonfiction, I find a source citation for a video on YouTube. When I paste the URL into my browser, I get the “This video isn’t available anymore” page. General searches on the associated subjects of the video don’t turn up anything, and the author can’t find it, either. What should I do? Can we cite a ghost source, with a note indicating that it has vanished? Or do we have to jettison the source citation and associated quotations?
A. You say it’s an anthology, which would generally mean that the article or essay or whatever would have been previously published. In that case, we’d recommend leaving both the text and citation as originally published; then, to save readers the trouble of chasing after a bad link, you could add “[video no longer available]” or the like in square brackets after the original citation (see also CMOS 2.44 and 6.99).
If, however, you were editing a previously unpublished document, then it would be better to revise the text to eliminate any reliance on the video (or ask the author to do so). To avoid this unfortunate scenario, authors should always save a copy of any source that might be subject to disappearing—for example, via the Save Page Now feature at the Internet Archive’s Wayback Machine. (The forthcoming CMOS 18 will show how to cite a source that’s been archived in this way. Or see this recent Q&A for an example.)