This technique was documented by Erland Sommarskog, SQL Server MVP in 2004. The XML and other methods can be found in the classic article "Arrays and Lists in SQL Server".

For SQL Server 2000, see http://www.sommarskog.se/arrays-in-sql-2000.html and for SQL Server 2005, see http://www.sommarskog.se/arrays-in-sql-2005.html