EXERPT FROM VFP helpfile...

SET UDFPARMS TO VALUE | REFERENCE
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Tip Entire arrays can be passed to a procedure or user-defined function. The entire array is passed if you issue SET UDFPARMS TO REFERENCE or preface the array name with @. The first element of the array is passed by value if you issue SET UDFPARMS TO VALUE or enclose the array name by parentheses. Array elements are always passed by value.
{end exerpt}

HTH