I Can't find these in documentation

I tried to enable My Reports in Site Settings as suggested by Microsoft Documentation for SQL Server 2008 Documentation,

http://msdn.microsoft.com/en-us/library/ms155826.aspx

but I cannot find any control (Radio button, check box) in Report Manager's Settings page to enable My Reports.




In Report Manager | Site Settings | General there is this item,

Custom Report Builder launch URL:

I also cannot find documentation about this item,

I appreciate if any reader of this blog has some idea about these.