Child -> Parent(s) Relationships

We currently have Parent with multiple children ability.

It would be most useful to have Child with Multiple Parents ability in core.

There are currently two modules in contrib. - but I find them rather complex to use and understand.

thank you for considering this and all your hard work to keep this Summer project active.

I know I'm suppose to explain why I think this is important - but it seems the more I try to explain this type of stuff - the more I confuse people :-)

I think you can see the possibilites of this feature.

best regards,