OK, I've found that there is zsh-beta-doc package. So some files should be removed from /usr/share/doc/zsh-beta dir, for example,
/usr/share/doc/zsh-beta/examples and /usr/share/doc/zsh-beta/zsh.texi.gz -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
