Originally Posted by
DeltaFFATL
Regardless, I still think the 24-cxl only applies for tickets bought solely from DL with no other party involved. Thus, DL.com from start to finish or over the phone with a DL agent.
Since this is a DOT rule, I think it's required no matter what ticket purchasing method:
http://www.dot.gov/affairs/2012/dot0812.html