one set of double quotation marks (“ ”), as usually appear around quoted material.
Quoting Accurately With SicSic indicates that the word or phrase it follows has been written or spelled in the same way it originally was, even though it appears to be a mistake. Writers often use sic (which comes into English from the Latin word for so or thus) when they’re quoting material from another source. The use of sic lets the writer off the hook for any spelling …
Compare single quotes.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019