An article processing charge (APC), also known as a publication fee, is a fee which is sometimes charged to authors. Most commonly, it is involved in making an academic work available as open access (OA), in either a full OA journal or in a hybrid journal. This fee may be paid by the author, the author's institution, or their research funder. Sometimes, publication fees are also involved in traditional journals or for paywalled content. Some publishers waive the fee in cases of hardship or geographic location, but this is not a widespread practice. An article processing charge does not guarantee that the author retains copyright to the work, or that it will be made available under a Creative Commons license.