URL for schema for web.config

Is there a URL to access the official schema for web.config?

Does the official web.config schema recommend a canonical order for sections and elements within sections so that it is easier to compare different web.config files in a diff utility? Otherwise it is necessary to use an XML aware diff utility that ignores the order of sections and elements when doing the comparison of the different files.

I want to be able to easily compare different versions of web.config to find where the differences are. I would also prefer to use a canonical order for elements in web.config if in fact Microsoft ASP.Net has recommended such an order. That way, different web.config files will be somewhat more consistent with each other in the order of their sections and elements.
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