The most common example is a document that lacks well-formedness.
最常见的例子是缺乏良好格式的文档。
2
XMLStreamWriter provides methods for writing individual XML tokens (such as opening and closing tags or element attributes) without checking their well-formedness.
XMLStreamWriter 提供了写入单个 XML 记号（比如开始和关闭标记或者元素属性）的方法，不检查这些标记是否格式良好。
3
The XML 1.0 well-formedness definition specifically states that attributes are unordered, but says nothing about elements.