I came accros this interesting page that holds snapshots of the FreeBSD release documentation, for the most recent versions back to version 4.5.

This page holds snapshots of the FreeBSD release documentation. The first released version of FreeBSD to use RELNOTESng was 4.4-RELEASE.

For each release, this page holds HTML, TXT, and PDF renderings for all supported architectures. These files generally contain the same content as what can be found on the various released distributions (e.g. floppy, CD-ROM, or FTP areas), except that the errata file has been updated to the latest version applicable to each release.

Snapshots of the release documentation (also in HTML, TXT, and PDF) for the CURRENT, 7-CURRENT, 6-STABLE, 5-STABLE, and 4-STABLE development branches are also provided here. Almost by definition, they are continually changing; typically they track the state of developments to within a week or so. The snapshots here are manually regenerated from the heads of the respective CVS branches on an irregular, but fairly frequent, basis.