An addendum or appendix, in general, is an addition required to be made to a document by its author subsequent to its printing or publication. It comes from the gerundive , plural , "that which is to be added," from (, compare with memorandum, agenda,

corrigenda An erratum or corrigendum (plurals: errata, corrigenda) (comes from la, errata corrige) is a correction of a published text. As a general rule, publishers issue an erratum for a production error (i.e., an error introduced during the publishing pr ...

Specific uses

In books

An addendum may explain inconsistencies or expand the existing work or otherwise explain or update the information found in the main work, especially if any such problems were detected too late to correct the main work. For example, the main work could have had already been printed and the cost of destroying the batch and reprinting it deemed too high. As such, addenda may come in many forms—a separate letter included with the work,

text file A text file (sometimes spelled textfile; an old alternative name is flatfile) is a kind of computer file that is structured as a sequence of lines of electronic text. A text file exists stored as data within a computer file system. In operat ...

s on a digital medium, or any similar carrier. It may serve to notify the reader of errors present, as errata.

In contracts and other legal documents

In other documents, most importantly in legal

contract A contract is a legally enforceable agreement between two or more parties that creates, defines, and governs mutual rights and obligations between them. A contract typically involves the transfer of goods, services, money, or a promise to ...

s, an addendum is an additional document not included in the main part of the contract. It is an ad hoc item, usually compiled and executed after the main document, which contains additional terms, obligations or information. An Additional Agreement to a contract is often an addendum to a contract and is simply referred to as being an extension or addition to a main contract. In today's business world additional authorisation subjects such as company seals are not usually required unless stipulated in the original agreement. It is to be distinguished from other appendices to a contract which may contain additional terms, specifications, provisions, standard forms or other information which have been separated out from the main body of the contract. These are called: an ''appendix'' (general term), an ''annex'' (which includes information, usually large texts or tables, which are independent stand-alone works which have been included in the contract, such as a tax table, or a large excerpt from a book), or an ''exhibit'' (often used in court cases), Similarly an ''attachment'' is used usually for e-mails, while an ''enclosure'' is used with a paper letter. Addenda are often used in standard form contracts to make changes or add specific detail. For example, an addendum might be added to a contract to change a date or add details as to delivery of goods or pricing. The addendum should be referenced in