The icon behind a link marks it as a document, which is no longer accessible directly from its original destination. This usually causes a so-called "404" error, when accessing the document. Linux installation reports are a valuable resource, we have therefore re-directed these links to the WebArchive(http://web.archive.org/) but you may also use the Google Cache(http://www.google.com/intl/en/help/features.html#cached) or other means.
If an external link has changed or isn't valid anymore, please let me know.
Other means, e.g. persistent identifiers for web documents, will be taken into account later: