With the recent changes to the Battle/Extract screen, their is no better time to address the HOST identifier issue.
As you know Warframe imploys a 4 person squad with one person holding the position of host and the other 3 being clients.
The host is very important, as their actions affect all the members of the squad. That said it should be commonplace for all the clients to be able to easily recognize who holds the position of host.
However this is furthest from the truth in Warf