I may be wrong, but as far as I know, you cannot create a system stored procedure--they are provided by Microsoft only.

You will find articles on the internet that will tell you by prefixing a stored procedure with sp_ and storing it in the master database you're creating a system stored procedure, but as Christian has already pointed out, you're not.

If MS ever decides to come up with a (real) system stored procedure that uses the same name as your user stored procedure, your code will be disregarded and won't execute any more.

Regards,

Michael