QUOTENAME

QUOTENAME returns a Unicode string with the delimiters added to make the input string a valid SQL Server delimited identifier.

SELECT QUOTENAME('abcdef') --result: [abcdef]

SELECT QUOTENAME('abc-def') --result: [abc-def]

SELECT QUOTENAME('abc[]def') --result: [abc[]]def]

http://msdn.microsoft.com/en-us/library/ms176114.aspx