Anaddendum orappendix, in general, is an addition required to be made to a document by its author subsequent to its printing or publication. It comes from thegerundiveaddendum, pluraladdenda, "that which is to be added", fromaddere[1] (lit. ''give toward'', compare withmemorandum,agenda,corrigenda).
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 files on a digital medium, or any similar carrier. It may serve to notify the reader of errors present, aserrata.
In other documents, most importantly in legalcontracts, 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: anappendix (general term), anannex (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 anexhibit (often used in court cases),
Similarly anattachment is used usually for e-mails, while anenclosure 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 the contract, or the contract should be referenced in the addendum, so that it is clear which contract the addendum is modifying.
Arider is often used to add specific detail and especially specific conditions to astandard contract such as an insurance contract. A rider may also be added toa piece of legislation.
Schedules andexhibits are sub-categories of addenda, with schedules being related to numerical and time information, such as pricing and time-schedules, and exhibits used for examples of standard forms or additional information necessary for the parties to understand and/or comply with their contractual obligations. Outside of contract law, exhibits are often used in legal documents filed with a court as part of judicial proceedings such as motions, briefs and the submission of different types of evidence for inclusion in the record of trial of a particular case.
Juries in inquests or trials may amplify or explain their decisions by issuing a commentary known as arider, as in the prosecution ofHarold Greenwood[2] and the inquest ofJean Charles de Menezes.[3] This practice persisted in the United Kingdom and Ireland until the 1970s.[4] In inquests, these riders influenced decisions by local authorities regarding physical infrastructure, and decisions by employers about safe working practices. In trials, they influenced the sentencing decisions of judges, and the decision by central government whether a particular person convicted of a capital crime should be executed.[5]
Addendum is also used if the medical care staff is inserting additional information about the patient.
The addendum is theradial distance from thepitch circle of a cogwheel, worm wheel, etc., to the crests of the teeth or ridges. This is also the radial height of a tooth above the pitch circle.
