I'm looking to do a SDC in a few days to fly ABC-JFK-XYZ instead of the original ABC-DTW-XYZ. It looks likely that the ABC-JFK flight will go to Y0 before the flight, so I may have to standby for it. Reading the terms on .dumb, it states:

JFK-XYZ has a ton of open seats and will likely remain that way until the departure date. If I opt to standby for ABC-JFK and clear the list, will I arrive in JFK as a standby passenger or will I clear the JFK-XYZ flight (assuming space is available) once the ABC-JFK flight clears.

I realize that it makes no sense for DL to confirm me on a second segment of a connecting itinerary if I am yet confirmed on the first, but it's not clear to me what happens when I am moved to the cleared list for the first (ABC-JFK) segment.

I was told once that you had to standby for the entire trip and not just parts of it. If you didn't clear for the entire trip you wouldn't clear.

Have no clue what DL will do, but if it was me I would just call in after boarding ABC-JFK to get the SDC confirmed on the 2nd leg.

What JKP said is true...standby for both legs. BUT...as is the case...you'll probably be able to find someone who'll confirm the second leg.