Spoiler ahead if you don't know March of Sacrifices dungeon.
Specifically, I have in mind the boss fight from March of Sacrifices where in Wyress Ursus uses a power bash attack that will apparently one shot anyone who blocks that is not a tank (those who are not tanks much dodge). In a random normal dungeon last night, two people dropped (one dps and the tank) and the healer and I tried this fight, but despite blocking his big attack, it would one shot us (didn't know about the need to dodge at the time). I guess I can see in daily dungeon who is the tank, since roles are specifically selected. But what about when grouping with friends, for example? How is a tank defined for something like this? Is a tank simply defined by taunting?