If you haven't deleted your account, I don't think anyone answered your question correctly ...
It sounds like you're talking about 'calltag' pickups. They will show in your board along with deliveries, scheduled pickups, and on-call pickups. When you get to the address, you scan the label. Per company training, make a legitimate attempt: knock, ring, bellow out "UPS!" Wait around a bit, listen for any sound that someone's home, and repeat. If it's a business, obviously you go in and make contact to get the return.
At this point, you need to know there are generally 2 types of calltags. RS1 and RS3. This will be in bold at the top of each label. (There are also Damage call-tags but those are rare.) If no one's home, you leave an RS1 calltag at/near the door. Follow the prompts in the DIAD (it's pretty self-explanatory, e.g., 'Left Tag' and '1 - Resi'). Your center may have the new doorhanger bags so it's easy to leave them on the doorknob. Otherwise, as close to the door as possible, e.g., partially under the welcome mat, etc. If they're home and the return pkg is ready, you take the pkg, and put the label on, follow the prompts and stop complete. If they're home and the pkg isn't ready, you leave the tag.
If it's an RS3, same process except -- you never leave the tag, even if the customer asks you to do so. If they're not home, sheet it NI (not-in)-1 with a filled out infonotice. If they're home but the pkg isn't ready, sheet it NR (not ready)-1, and let the person who answers know we'll try 3 times to pickup the pkg, urge them to have it ready ASAP tmrw if it's the 1st or 2nd attempt. In both cases, fill out the back of the tag and bring it back with you to the pkg car. You'll turn it back in at the center that night. If they're home and the pkg is ready, same process as the RS1 calltags except there won't be a prompt when you scan it. Just hit stop complete and 1-resi or 2-comm.
Sometimes people will say they cancelled the return. So in that case you'll go to non-delivery menu, Other, Refused, and assign it cancelled. Other times people have no idea what you're talking about: Non-delivery, Other, Refused, Didn't Want. If no one with that name lives at the address: Non-delivery, Other, No Such Person. In all of these cases, you take the tag back to the center, likewise if they've put 4 different Amazon returns in a single box. You use 1 label, sheet it appropriately, and sheet the rest as Refused and take them back to the center.