Interesting. Once miles are in Diners, they can be used for BA awards etc. Although with the massive hikes in the BA chart recently, much of that attraction has gone.

Surely Diners or UA is the only one that could stop the transfer UA-Diners?

I can understand HH have the right to stop Diners-HH, but anyway aren't DINERS then responsible for paying Hilton, as it has zippo to do with UA at that point?