In TTS, you can pick up any posted trip outside of a TTS run. Just click the shopping cart and pick it up. If it's not posted, but balloted, you need to put it in your ballot and let it run to see if it meets their ballot requirements.
If a trip is posted in DECS, go to the N4 in TASC sabre, find the trip, and go through the steps to pick it up, you can even run it in test mode just like you could in LS. If it is posted you don't need any action from the person dropping the trip.
The only thing we really lost with LS was Pilot to Pilot auto trade. There is no mechanisim in TASC Sabre / DECS to automate that process. That is where the authorization part comes from so you can't just screw with someone elses schedule. When something is posted for drop that is the authorization.