I noticed today that the user manual administration chapter (administration.txt) contains information about specific older releases, which is stale.
In particular, it contains assertions about the stability of specific combinations of Accumulo, Hadoop, and ZooKeeper versions, for older Accumulo releases, based on testing. This information is not appropriate for the user manual, and would be better presented in the release notes for particular releases. The user manual should be written agnostic to the current version, whenever possible.
Additionally, the client configuration section contains information about version 1.6.0, in the present tense. Change in behavior at a version boundary should be written in such a way as to convey that a the behavior changed (past tense) across that boundary, rather than be written to correspond to the current release.