The case-sensitivity of document language element names in selectors depends on the document language. For example, in HTML, element names are case-insensitive, but in XML they are case-sensitive.

• 选择器中文档元素名称是否大小写敏感取决于文档语言.；比如在HTML中；元素的名字是大小写不敏感的；而XML中则是敏感的