```On 01/06/2012 11:47, Marco Daniel wrote:
> Hi,
>
> If you use the command \DeclareDocumentCommand and the command name
> already exists, you will get the warning "LaTeX warning
> "xparse/redefine-command" " initialized by
>
> \msg_kernel_warning:nnxx { xparse } { redefine-command }
>
>
> I think most package authors will use this command. (e.g. fontspec)
>
> Based on this fact you will get a lot of warnings. In my opinion
> warnings become ineffectually.
>
> So I suggest to use \msg_kernel_info:nnxx { xparse } { redefine-command }
>
> What do you think?

This is 'by design'. The reasoning is that altering an existing command
potentially changes the interfaces defined in a document, and so
deserves a warning in the log. You can of course redirect these warnings