Assignments are given at the NPC corporate level and the relations to that corp determine what each player can do. But everything regarding terminal/outpost services talk about your relationship with the station/outpost, yet the relations tab in the agent window doesn't say anything about your relationship to anything but the corps. The guide and in-game help should explain how corp standings are used to calculate relations with stations/outposts and these relations (both the formula and total) should be displayed somewhere (either agent window or somewhere else in the terminal view).