The syntax for declaring parameters : Parameter « Procedure Function « SQL Server / T-SQL Tutorial

@parameter_name_1 data_type [= default] [OUTPUT]
[, @parameter_name_2 data_type [= default] [OUTPUT]]...
Typical parameter declarations
@DateVar smalldatetime           -- Input parameter that accepts
                                 -- a date/time value
@BankerVar varchar(40) = NULL    -- Optional input parameter that accepts
                                 -- a character value
@InvTotal money OUTPUT           -- Output parameter that returns
                                 -- a monetary value

21.13.1.The syntax for declaring parameters
21.13.2.Parameterization: @parameter_name [AS] datatype [= default|NULL] [VARYING] [OUTPUT|OUT]
21.13.3.Procedure with default parameter value
21.13.4.Check parameter value with if statement
21.13.5.Procedure with two parameters
21.13.6.Passing the ORDER BY Column as a Parameter, Using a Column Number
21.13.7.Passing the ORDER BY Column as a Parameter, Using Dynamic Execution
21.13.8.Select using value from parameter
21.13.9.Call procedure with parameter name
21.13.10.Parameter with null default value
21.13.11.Pass column as the parameter
21.13.12.parameters can be passed explicitly by value
21.13.13.stored procedure can be executed with the parameter and assigned value
21.13.14.Wildcards in Parameters
21.13.15.Check value range for input parameter
21.13.16.Code that omits both optional parameters
21.13.17.Code that omits one optional parameter
21.13.18.Code that passes the parameters by position
21.13.19.Code that passes the parameters by name
21.13.20.Stored Procedure with Cursor Parameter