The Parameters tab of the Function property sheet has the following components:
Parameters list Displays the name, ID, data type, parameter type, and mode of the function's parameters. The mode has one of the following values:
In The parameter is an expression that provides a value to the function.
Out The parameter is a variable that could be given a value by the function.
In/out The parameter is a variable that provides a value to the function, and could be given a new value by the function.