Schema for non-numeric types. The domain item type indicates that an element is a domain or domain member. Domain item types may or may not have attribute abstract="true". escapedItemType specializes string. There is no constraint on whether the content resulting from XML un-escaping is well-formed or not. It is a suitable base type for (say) a data type whose unescaped content must conform to an SGML DTD. xmlNodesItemType specializes escapedItemType. The unescaped content MUST be a sequence of XML text and well-formed XML nodes. This content constraint cannot be captured by a finite length regular expression. 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. textBlockItemType specializes xmlNodesItemType. The unescaped content MUST have mixed content containing a simple string, or a fragment of XHTML or a mixture of both.