Описание тега sqlxml
SQLXML is a feature in MS SQL (introduced in SQL Server 2000), that enables XML support for making queries and processing data.
SQLXML was introduced in MS SQL Server 2000, and adds support for MSXML library into SQL Server. It allows the user to execute SQL SELECT statements that return XML instead of tabular data. In later versions(from SQL Server 2005), the XML support was extended with adding xml as a type in MS SQL Server to support XPath and XQuery over tables.
More info can be found in SQLXML's page in MSDN: http://msdn.microsoft.com/en-us/library/aa286527.aspx