Within XML there exits elements and attributes. There is a special attribute called xsi:type. Can an element have two xsi:type declarations? Example using Dublin Core.
Element Example
<dc:date>1091</dc:date>
Attribute Example
<dc:date xsi:type="dcterms:dateCopyrighted">2022</dc:date>
Question: Is the following Valid?
<dc:date xsi:type="dcterms:dateCopyrighted" xsi:type:="dcterms:W3CDTF">2012-11-11</dc:date>
I've looked in various W3C documents and various XML books. I can't find anyone talking about two instances of xsi:type. My suspicion is that the second type will overwrite the first especially if the two values are in the same namespace as is provided in the question example.
No, there cannot be two xsi:type attributes on the same element because XML in general prohibits any two attributes from having the same name:
3.1 Start-Tags, End-Tags, and Empty-Element Tags
Well-formedness constraint: Unique Att Spec
An attribute name must not appear more than once in the same start-tag or empty-element tag.