On Thu, May 28, 2015 at 9:39 AM, Ben Coman <btc@openinworld.com> wrote:

On Thu, May 28, 2015 at 5:48 PM, Sergio Fedi <sergio.fedi@gmail.com> wrote:
> (Personally I have no idea of Work criteria to list classes, and have no
> idea of the details of the other two)

Neither do I.�� Never used them.�� Now I wonder if when you define a new
group, you might also define a filter and the existing groups use that
facility, such that you could inspect and existing group to see its
definition.