Originally Posted by
shuom
Just a newbie question, what's the difference between the two?
Upgrade eligible just means you can request a complimentary upgrade. But without the request, you are flying in back. There is a little tick box when you book the ticket to "Request Upgrade". By default it is checked. But for some reason even if you have an Upgrade Requested, occasionally Delta.com will change it back to Upgrade eligible and you need to re-request it.