The most current HP-UX 11i Release Notes can be found on the Instant Information media (in the HP-UX 11i v1 Operating System Collection) and on the HP Technical Documentation Web site at
Be sure to consult the edition most appropriate to your release. If you are concerned about the September 2005 release, for instance, then you should begin with the HP-UX 11i September 2005 Release Notes edition.
Note that the name of the initial HP-UX 11i release was simply "HP-UX 11i." Unlike its subsequent updates, it does not have a date in its name. Therefore, the release notes for the initial (December 2000) release of HP-UX 11i v1 are titled simply HP-UX 11i Release Notes.