http://finregont.com/fro/xbrl/dtr/non-numeric.ttl#XmlItemType
Class 'non-numeric:Xml item type'

http://www.xbrl.org/dtr/type/non-numeric#xmlItemType

owl:Class

xmlItemType specializes xmlNodesItemType. The unescaped content MUST be well formed XML. This is a suitable base type for elements whose content must conform to a specific XML Schema or DTD. This content constraint cannot be captured by a finite length regular expression, other than that "<" must be the first non-whitespace character and ">" the last non-whitespace character.

Xml item type

instance:Non numeric item attrs

non-numeric:Xml nodes item type