Relations in assignemnts are treated differently in user's assignment subtabs.
I will show that in Czech language, as in English it is not so clear. Screensohts are from demo.evolveum.com
But on Role, Organization, Service, the situation is different! All relation has name, but unfortunately, it is not translated. So the blu text below should be in Czech, like this: Vztah: Člen, Vztah: Manažer