I have a suggestion for documentation about tar (man, info).
I just learned today that when root uses tar the ownership of untarred files
will by default revert to the user who tarred the file in the first place. When
downloading a tarred binary, that could be a problem because the uid for the
files might not correspond on different systems.
The man page should contain a sentence or two about ownership of extracted
files. The info pages contain a short paragraph about it under "option
summary", (--owner=USER), but I think it needs more prominent mention.
Imagine my frustration when root was untarring something and all the untarred
files belonged to a user I hardly used anymore.
When extracting an archive, do not attempt to preserve the owner
specified in the `tar' archive. This the default behavior for
ordinary users; this option has an effect only for the superuser.