T- SQL usage of @$

I joined this new project and found a different way of declaring local vars in SQL Server Stored Procedures as

DECLARE @$prog VARCHAR(50),
        @$errno INT

I have always used @ to declare local variables in T-SQL, wondering when to use @$?

Please guide开发者_如何学运维.

This has no special meaning, the $-sign just happens to be legal inside an identifier. See the MSDN page on identifiers.