Use brackets to insert editorial notes into a quotation and to enclose parenthetical material within text that is already in parentheses. In a quotation, the brackets tell the reader that the added material is yours, not the original author’s. (See also P10.)

If the original quotation includes a mistake, add [sic], the Latin word for “so,” in brackets to tell the reader that the error occurs in the source. Often you can reword your sentence to omit the error.

Replace inappropriate brackets with parentheses.