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Citation, Documentation of Sources
Q. When a URL is the last item in a footnote, the period at the end of the note sometimes gets swept up in either a hyperlink or a copy-and-paste of the URL. When this happens, the link doesn’t work. Is there any movement to change the rule for punctuation around URLs to reflect this reality?
A. This debate crops up every now and then. The problem is that URLs are designed to work in the background, where they facilitate links (e.g., to CMOS Shop Talk); they weren’t intended to appear in the run of ordinary text. When they do, Chicago allows not only for periods (as at the end of a footnote, in part to accommodate any text that follows) but also for commas, as in https://cmosshoptalk.com/, and parentheses (cmosshoptalk.com)—and so on for other punctuation. This approach, which prioritizes the surrounding text over the URL, is also used for MLA style, whether in text or notes. APA, on the other hand, leaves out the period after a URL at the end of a reference. We have no plans to change our recommendations, but editors who follow Chicago (or MLA) can help by double-checking that the links—minus any surrounding punctuation—point to the right place.