Do what I swore would be done:
o Remove 4.X information, this includes notes and sections.
o Update documentation to reflect 5.X and 6.X.
o In some areas, try to make the new content version agnostic.
o Skip areas stating "5.[0-5] and later" as it's relevant - we
need a better way to handle these.
For several items, I checked the NOTES files, manual pages,
CVS history, etc.
Discussed on: -doc
A few ideas from: remko