Originally Posted by
GagaPilot
Interesting, as I did not realize that DL and HA did not have an official interline bag agreement, despite having the ability to sell tickets on each other's flights. The actual list in the link provided above was much smaller than I expected and I see some airlines missing that I know DL can interline with, but they must be by exception and not policy.
There are two different concepts here. DL and HA have a full interline agreement and have the ability to check through luggage to each other as they want.
The distinction is that both carriers refuse to check luggage across separate tickets between themselves (and many others) as a matter of policy. Airlines (including fancy Air Lines) have increasingly taken a firm stance against accomodations with separate tickets.
The way I describe it is that they could do it; however they both independently choose not to.
Some airlines are even more militant about it, AA, AS and BA refuse to check luggage on separate tickets even if both flights are on their own metal.