```Joseph Wright wrote:
> Will Robertson wrote:
>  > Another random thought: since users "shouldn't" be defining new macros
>> within the body of their documents, I think LaTeX3 should have something
>> like the equivalent of
>>   \AtBeginDocument{\catcode`\#=12}
>
> This of course would be a major break with LaTeX2e at the document
> level.  However, as everyone seems agreed that there is no real chance
> of compiling arbitrary LaTeX2e documents with a full LaTeX3 kernel, I'd
> say it is a design choice worth making.

But then I would say \catcode =12 to everything else, excluding only \
and maybe {} for grouping. Maybe even the meaning of % and \% could be
interchanged: % in normal Text and \% as comment?
Or is that too much changed?…

Cheers
Arno

```