RE: coding systems

[Drew Adams]

> By the way, on the subject of the virtue of code examples...  if
> I'd just given that a try on my own, I might very well tried a
> quoted string first:
> 
>   (prefer-coding-system "utf-8")
> 
> I would then have been very puzzled by this error message:
> 
>   error: Invalid coding system `utf-8'


This is a chance to help improve Emacs by submitting a bug report:
`M-x report-emacs-bug'. You can say something like the following:

The function's doc string should say what it expects as an argument - it should
say whether it is a string or a symbol or either (or something else).

(The same would be true of its treatment in the Elisp manual, if it were covered
there.)

IOW, you've learned something that isn't covered by the doc as it should be.
Please pass along that knowledge, to improve the doc and help others.