An element or attribute is qualified if it is explicitly assigned to a namespace. Consider the following example, in which the elements and attribute of <Person> are not qualified:
<?xml version="1.0" encoding="UTF-8"?>
<Root>
<s01:Person xmlns:s01="http://www.person.com" GroupID="J1151">
<Name>Frost,Sally O.</Name>
<DOB>1957-03-11</DOB>
</s01:Person>
</Root>
Here, the namespace declaration uses the s01 prefix. There is no default namespace. The <Person> element uses this prefix as well, so that element belongs to this namespace. There is no prefix for the <Name> and <DOB> elements or the <GroupID> attribute, so these do not explicitly belong to any namespace.
In contrast, consider the following case where the elements and attribute of <Person> are qualified:
<?xml version="1.0" encoding="UTF-8"?>
<Root>
<Person xmlns="http://www.person.com" GroupID="J1151">
<Name>Frost,Sally O.</Name>
<DOB>1957-03-11</DOB>
</Person>
</Root>
In this case, the <Person> element defines a default namespace, which applies to the child elements and the attribute.
Note:
The XML schema attributes elementFormDefault attribute and attributeFormDefault attribute control whether elements and attributes are qualified in a given schema. In InterSystems IRIS XML support, you use a class parameter to specify whether elements are qualified.