Correct. On domestic flights, it's up to the passenger to say "please tag it to Atlanta only"...and preferably watch the tagging happen.

I believe the policy is passengers can check to the connecting point if the connection exceeds 4 hours on a domestic/Canada flight/connection pair, or to the connecting point if on an international itinerary (excluding Canada) if the connection is over 6 hours.

The passenger must retrieve the baggage at the connecting point if the connection exceeds 12 hours, except in CDG and AMS where they can hold the bag for up to 24 hours to make the connection.

If you are on US/DL/AA, do not count on being able to short-check a bag on a connection which does not include an overnight.

I have been on RJ flights where they did not "valet" check pink tagged bags and actually sent them to baggage claim. Thankfully I was not connecting that evening.

That's fine if I know that I'm checking bags in advance, but if I show up at the airport with the expectation of being able to carry on, and am forced to check, I will demand a short check if necessary.

The best time to do Hidden City Ticketing is on International flights where you will need to check your bag to your final destination. Instead of placing your checked luggage on the belt you leave the airport and call up the airline or tell an agent to cancel the last portion. Its not an everyday practice but I did it once last year from LAX-TLV-LAX on a $944 United Ticket when they were advertising the same nonstop flights for $1300+. I had a free ticket on Alaska to LAX.

It worked out well on the return. We arrived at 4:45 AM and Customs opened at 7:00 AM. When I arrived into SFO during the wait for Customs to open i called up United to tell them tat I would not be taking the flight down to LAX and I informed my travel agent too. As the ticket cost to change the flight would cost me more than flying down to LAX I just let it go as I saved so much money doing it this way. I was through Customs and in my car at 6:20 AM and home at 7:00 AM vs having to fly down to LA and back home.

IRROPS is the biggest risk to hidden city - it's the one thing outside anyone's control. One can carry on luggage and board with boarding group to avoid gate checking. But IRROPS can result in being "rerouted" through a different connecting point which blows your plans - good luck convincing an agent to keep your original routing. I remember a post on Flyertalk many years back - someone booked SJC-LAX-LAS (on American) with the intention of getting off at LAX. SJC-LAX was significantly delayed which meant he would have "misconnected" and he was rebooked on SJC-PHX-LAS.

And if the flight is overbooked, don't volunteer to give up your seat no matter the offer. Like IRROPS you could be rerouted through a different hub.

What ridiculous hyperbole. No "good luck" needed - you can change the routing or itinerary yourself online, or in the app, when IRROPs happen.

On top of that, you don't have to accept what they automatically offer/rebook you on, either for IRROPs or VDB. You can accept it, or you can select anything else with any availability to change onto.

Sure, but only if flights to your original connection point are available.

Good idea to check alternate flights before trying hidden city ticketing.

The issue is "something with availability" lining up with your schedule. Doing hidden city via ATL is probably less of an issue because ATL tends to have the most daily options from most cities. But other hubs don't. If for example, you book BOS-LAX-SAN to do hidden-city on BOS-LAX, well, BOS-LAX runs early in the morning and then not again until mid-afternoon. Now, DL can easily get you to SAN via ATL, MSP, DTW, SLC, JFK, etc but you may not be able to wait until mid-afternoon for the next BOS-LAX nonstop, assuming it even has availability. Now on the opposite side of the coin, DL is usually pretty flexible with IROPS. You might be able to ask for BOS-HUB-LAX, as in that situation it's not unreasonable for someone to say "my final destination is as close to LAX as it is to SAN - it doesn't matter where you get me to" when the alternate option is reasonable. Point is hidden city is all still a gamble. In many cases, it probably works out without any issues but there is the potential of things going horribly wrong that people should be aware of if they're even considering it and it's not up to the airline to figure out how to fix it.

I mean, yes, don't do it if yours is the only flight with that routing for several days? How often is that a concern?