> The standard recommendations are:
>
>   1. Stop wanting that.
Ok, then I have to deal with more complex code for the xml-export.
And the human editors of the xml files are more restricted.

>   2. Use a more powerful schema definition language.
What do you mean with this?

>   3. Validate on application side, not on parser side.
The application already parses the files, but for offline usage I
would like to have the possibility to check against a schema, perhaps
with a simple xmllint.

>   4. Design a well-structured document:
>
>       <temperature scale="celsius">27</temperature>
>       <sky>cloudy</sky>
>
The sample provided above is not the original document. It just a
simplified example to describe the problem.
I think I described a quite well-structured schema already :-)

> Another interesting way of dealing with modestly crippled
> XML documents is transforming them into something sane
> using XSLT. Make the transformation scream and swear if it
> runs into something that shouldn't be there, and you're
> golden.
>
The documents will be generated by my application, but can be modified
by a human user. The schema should be a guideline which modifications
are allowed.

Thanks,
Sven