According to XML specification (https://www.w3.org/TR/2008/REC-xml-20081126/#sec-common-syn), a colon is allowed as a NameStartChar. However, Namespaces in XML 1.0 (https://www.w3.org/TR/xml-names/) specified that element and attribute names MUST match the production for QName and all element and attribute names contain either zero or one colon (are UnprefixedName or PrefixedName).
Namespace-aware parsers shall therefore reject names with a colon as the NameStartChar.
The bug was introduced in JDK 6, coincided with the addition of StAX.
Namespace-aware parsers shall therefore reject names with a colon as the NameStartChar.
The bug was introduced in JDK 6, coincided with the addition of StAX.