Dijonnaise™ is a trademark/product of CPC, which markets its products as Hellmann’s east of the Rockies and Best Foods west of the Rockies.
I now see that CPC was bought out by Unilever, which I should have known, since I’ve seen their hypnotic logo on Hellmann’s packages.
D’oh! Yeah, Best Foods. That’s what I meant. I knew I’d never seen a Hellmann’s brand, but I was familiar with Dijonnaise 
Thanks!
Hells yeah! Nice rare roast beef on a poppy seed roll with a quarter inch thick layer of Hellman’s?? Yummy. Mayo also works on a cheeseburger.