I have spent about 45 minutes reading the sticky and searching this forum and the internet, and I am still not sure I understand the policy.

It appears the terminology applied to this by Delta is "Downgrading" a ticket.

It appears that in some cases the ASC fee (have been unsuccessful in finding out what ASC stands for, but it apparently just means a fee for changing something about the ticket). But the wording on Delta's site is confusing to me. I think, but I am not sure, that it means that if you buy tickets through Delta.com you usually don't have to pay any fee to downgrade - is that right?

But there are certain types of webfare where you do have to pay the ASC fee to save money - is that right? If so, how do I determine whether a fare is subject to the ASC fee for a subsequent downgrade?

The ASC fee for changes or downgrades to a domestic US ticket is always $50 - correct? (I see some places where it says $100, but $50 appears to be what the website has now).

And, last question - usually one get a credit for a future flight rather than a cash refund, right? Is that transferrable to another person or not?

I am asking all of this stuff because it affects my strategy for buying a ticket on Delta metal ahead of time. WAS-BLI is running about $325 for next summer right now on Delta - and there isn't a lot of competition on this route. It doesn't seem like there would be a whole lot of opportunity for this to get cheaper - but there is a long time to go before my travel and it could. The alternative, to fly to Vancouver, is much more expensive (almost always runs at leat $500 or $600), and the historical data seems to indicate this route is rarely cheaper (I don't have a clue as to why flying into Vancouver is always so expensive, but it is).