user defined function using Array

Good afternoon,
I have the following user defined function using Array function but it did not work.
Any ideas will be highly appreciated.
Dennis

Public Function Cov(Prefix As String)

Dim BIArray As Variant
Dim PDArray As Variant
Dim PIPArray As Variant

 'Coverage Replace
  BIArray = Array("", "B.I.", "BI-06", "BI-L/T", "BI1", "OTHER BI", "LIAB")
  PDArray = Array("_PD", "DP", "JPD", "P.D, " PD", "  PD", "   PD")
  PIPArray = Array("PI ", "PI", "PIP TRAN", " PIP", "  PIP", "   PIP")
    
  Select Case Prefix
  Case BIArray: Cov = "BI"
  Case PDArray: Cov = "PD"
  Case PIPArray: Cov = "PIP"
  End Select
  
End Function

Don't you need to search through each array in turn? Example for BIArray:

For i = LBound(BIArray) To UBound(BIArray)
    If BIArray(i) = Prefix Then
        Cov = "BI"
        Exit Function
    End If
Next i

thank you.
Actually I complexize the question which can be simplified as the following example:

Case "PI ", "PI", "PIP TRAN", " PIP", " PIP", " PIP": Cov="PIP"

thanks again the forum.
Dennis

"didn't work" is such a general statement. Can you elaborate? What didn't work? Did it give an error message? What would be a typical value for "prefix"? For a given value of "prefix", what do you expect returned? If it's returning the wrong value, what value is it returning?