Check namespace in xml string or URI?

Question

I always wondered how the XML handler handles URI namespace validation. is it row based or URI based? In other words, this is the standard URI for SVG

xmlns="http://www.w3.org/2000/svg"

suppose instead I write

xmlns="http://www.w3.org/2000/../2000/svg"

or

xmlns="http://www.w3.org/2000/svg/"

or even

xmlns="http://www.w3.org:8000/2000/svg"

Will these cases be recognized as svg namespaces (based on URIs) or not (string based)?

thanks

Edit : The fact that you can use a URN (e.g. uuid) makes me feel like it is string based, because you cannot apply the correct URLs / URIs for a URL similar to a URL. But maybe in this case it will work as a string?

. , . , URI (: , ..). ?

Answer 1

. URI .

http://www.w3.org/TR/REC-xml-names/#NSNameComparison

URI, , , . [. URI , , , , . ] , % - .