In elisp docs in the session "8.3 Creating and Interning Symbols" Line 162 have a bug.
> --Function: unintern symbole obarray
Shoud change to
--Function: unintern symbole &optional obarray
In doc-string of "unintern" is also error.
In GNU Emacs 25.1.1 (x86_64-w64-mingw32)
of 2016-11-16 built on LAPHROAIG
Windowing system distributor 'Microsoft Corp.', version 10.0.14393