"Be careful though, the eqm's awarded will follow CO's rules, not Delta's rules."

CO's rules say if you fly on a discounted fare on DL metal you only get 50% EQMs.

DL's rules say if you fly any fare on a partner's metal you get 100% MQMs.

So, if I am booked on CO metal, but give my DL SkyMiles number, wouldn't DL rules apply? And I would get 100% MQMs on DL for flying a partner?

Thanks for clearing this up!