C# Definition:

[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("00000103-0000-0000-C000-000000000046")]
public interface IEnumFORMATETC
{
    [PreserveSig]
    int Next(int celt, [Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex=0)] FORMATETC[] rgelt, [Out, MarshalAs(UnmanagedType.LPArray)] int[] pceltFetched);
    [PreserveSig]
    int Skip(int celt);
    [PreserveSig]
    int Reset();
    void Clone(out IEnumFORMATETC newEnum);
}