When writing a research paper, a formal document or a news story, it is sometimes necessary to point out a misspelling or inaccuracy in a quote from a document used in your research. The professional way to do this is to place the italicized word "sic" inside boxy looking brackets immediately following the error. This indicates that a mistake in a quotation belongs to the author of the reference material.
Use of Sic As an Editorial Mark
"Sic" is Latin for "thus." In writing containing quoted information from other authors, it is interpreted as meaning "this is how the original is written." For example, the name of an author, such as Edgar Allan Poe, may be misspelled in a quotation used in a literary research paper and require correction such as, "Edgar Alan [sic] Poe," with the word "sic" italicized. You only need to use the symbol when noting errors in research materials that must be true to their original writing. Italicization and brackets are necessary due to sic being a foreign word and needing to stand out as an editorial mark. In contrast, parentheses can't be used, because they indicate asides -- thoughts somewhat distant from but related to what you are writing.
When Not to Use Sic
It isn't necessary to correct a misspelling if paraphrasing, which involves putting a quote in your own words. Also, when writing informal work documents, such as memoranda in which you quote supervisors or coworkers, it is better to correct misspellings than to point them out.