Citation, Documentation of Sources

Q. Are there any conventions yet for citing a text on Kindle? That is, because the type size is variable, there are no page numbers in a Kindle edition; instead, there is a running locator at the bottom of each screen. I’m wondering whether it would be permissible to cite these location numbers rather than look up my quotes in a hard copy of the text.

A. Yes, you can cite the location numbers, although unless a reader has the Kindle edition of that work, the numbers will be of little use for finding the text. Like unpaged online content, Kindle editions are best cited with reference to chapter titles or numbers, subheadings, or a unique phrase that can be located by searching. For more details, including examples, see CMOS 14.160.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]