Admiralty

In the first Star Trek film, there is a scene where Admiral Kirk strides purposefully through Star Fleet Headquarters among bustling uniformed personnel. He speaks to a Vulcan and there are probably other species present. In Gene Rodenberry's novelization, the Vulcan thanks Kirk for recommending him as the new Science Officer of the Enterprise. As a Vulcan, he does not believe that it is necessary to thank anyone else for a position that he would have won on his own merits. However, he knows that to say "Thank you" is the human custom and also knows from Spock that this human being is particularly worthy of respect.

In Poul Anderson's The People Of The Wind, Daniel Holm, Second Marchwarden of the Lauran System, strides through the Lauran Admiralty building, surrounded by naval personnel, civilian employees and more Ythrians than human beings. The former species is less numerous on Avalon but several are here from elsewhere in the Domain, including Ythri.

Holm goes to confer with First Marchwarden Ferune of the Mistwood Choth. Ferune's honor guard salutes Holm and admits him.

"(Holm did not tolerate time-wasting ceremoniousness in his department, but he admitted its importance to Ythrians.)" (Rise Of The Terran Empire, p. 454)

Thus, a Vulcan acknowledges a human custom and a human being acknowledges an Ythrian custom. In both fictional universes, the characters respond to a crisis.