where do I find a detailed description of all the XML element attributes in a VTU file?

I’m trying to find where I can get all the available attributes for the various elements in a VTK XML file, for example the element in a VTU unstructured grid file. I have some examples but I’m pretty sure they don’t cover eveyrthing, for example, they have examples of point and vector data but not of tensor data (assuming tensor data is supported). Thanks in advance and apologies if this is a duplicate question.

Check out VTKFileFormats