I have been trying to read tutorials on aliases and the quest alias tab and I am confused where in the creation kit, one assigns possible values for aliases. I am currently looking at the companions quest CR13 because I have played through it recently and I know that there are only two possible values for the alias, QuestGiver, Farkas and Vilkas. This is the quest where you cure one of them of Lycanthropy.

I click on the Quest Aliases tab and then click on the QuestGiver alias, and I have read through all the information here. I have a feeling that the alias is filled by what you select in the "fill type". However, if this is the case, I don't understand how each of the options work. Can someone explain this to me, or point me to a clear tutorial.

I apologize if my question is confusing, but I have trouble explaining things I don't really understand. If anyone thinks it is unclear I will attempt to make it clearer. Thanks for your time!