I want to know what this function parameter means？

        

Public Function CopyTo2( _

   ByVal pParent As ObjectItem, _

   Optional ByVal bWithObjects As Boolean = True, _

   Optional ByVal bWithSignals As Boolean = False, _

   Optional ByVal bNoCopyBin As Boolean = False, _

   Optional ByVal eCopyType As AucCopyType = 0, _

   Optional ByVal Target As ObjectItem = 0, _

   Optional ByVal SourceMerge As ObjectItem = 0, _

   Optional ByVal opMode As Long = 0 _

) As ObjectItem