> File: /src/Demo/Css/Template.css
>
> You agree -- it should have a label/tag/name that is logical and not a representation of it's physical location.
>
> Maps to: Demo\Css\Template

So how would we come from `Template` to `Template.css`?

* If you intend to automatically append the extension based on the scheme, e.g. `css:///Demo/Css/Template`, then this doesn't really make sense to me. If you list an extension as scheme or extension does not make a difference.
* If you intend to search for a file matching the name `Template.*` on the file system, this is where we would clearly cross the line and run into a Non-Goal, namely file search. As I see it, the resource locator should be responsible for a deterministic URI→Path mapping. Everything else is in the realm of search tools, such as the Symfony Finder component.

So yes, I'd say `Demo\Css\Template` should not be done, unless `Template` refers to a directory named so.