Basically, it says 100% test (includes everything , even mounting
holes) using the following parameters:
                          continuity resistance (max.)    isolation
resistance (min.)
        Class 1   50 ohms                                      500K ohms
        Class 2   20 ohms                                      >2 megohms
        Class 3   <20 ohms                                   > 2 megohms
        Nets that start on one side and end on the other require
double-sided (e.g. clamshell) test.
        I just looked it up. (IPC-ET-652, Oct. 1990)

> ----------
> From:         Ed Cosper
> Sent:         Thursday, July 1, 1999 5:23 AM
> Subject:      IPC test standard
>
> Hi all,
>
> I have a requirement to test boards to IPC-ET-652  section 4.4.  I do not
> currently have spec.  Can someone tell me what section 4.4 of this
> standard says.
>
> Thanks,
>
> Ed Cosper
>