Undefined key sequence in refcard.tex

[Sven Joachim]

Line 424 of etc/refcard.tex looks like this:

\threecol{display buffer in other window}{C-x 4 C-o}{C-x 5 C-o}

From the context of this, I concluded that C-x 5 C-o would display a
buffer in another frame, but actually C-x 5 C-o is undefined.  And
there is no command like `display-buffer-other-frame'; people who want
that will have to set `pop-up-frames' to t.

In GNU Emacs 22.0.50.1 (i486-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2006-03-16 on debian, modified by Debian