"Writing a document and putting it under revision control is not an easy task. One might want to make that document into a printable format and face several markup errors. One way to prevent that is to ensure that only correct DocBook documents are available to everybody and authors don't put problematic or with an incomplete structure at the repository. ... CVS allows the use of triggers in some stages. By using commit triggers we can start a validation proccess (in our case using onsgmls, from [[WWW]] OpenJade) that will either accept the document as valid SGML or refuse it."