Re: Document option tool-bar-mode

[Richard M. Stallman]

           But at this stage the Customize interface has not even been 
mentioned.
           How could a user new to Emacs, who reads the manual back to front,
           understand this any other way than to set the variable without using
           Custom?  He does not even know about Custom's existence yet.

       I don't think this is a problem.  The user will probably
       look at the chapter on customization and find various ways
       to do it.

    Except that not all of these ways work in this case.  The one he
    probably already knows does not.  I should have mentioned that setting
    `partial-completion-mode' (and `tool-bar-mode') _only_ works when set
    through Custom.

If this case is of that kind, then I agree it should mention M-x
customize explicitly.