Originally Posted by
jdrtravel
I'm sure that this part of your comment is really helpful to OP, thanks for your contribution.
It's helpful to everyone on FT (and in life, in general) if folks look for answers to basic questions on their own before starting a new thread to ask about something clearly spelled out on DL.com.
While I already knew the answer to OP's question, I also just found it in less than 10 seconds -- Went to Google and searched "delta global upgrades" -> first result was
https://www.delta.com/content/www/en...-upgrades.html -> scrolled to the section about using global upgrades. Verbatim:
"Redemption on Delta:
Valid for a one way upgrade on Delta and certain Delta Connection® carrier operated flights.
...
Redemption on partners: waitlist and standby not permitted.
...
Redemption on AIR FRANCE
Valid on most transatlantic flights operated by Air France.¹
One-way upgrade from Main Cabin when booked in Y, B, or M class to Premium Voyageur Class.
or
One-way upgrade from Premium Voyageur when booked in S or W class to Business Class.
¹ Not valid on AF operated 747 aircraft flights; only valid on flights with the Premium Economy Cabin.