by DocCool
You can only take a particular advanced tech tile if you're on or above level 4 of one particualar tech track. So what place would be better for the placement of that advanced tech tile than a) next to/on the assigned tech track and b) next to level 4? They also put some iconography on the advanced tech tiles resp. around their holding spaces which hints at what is required to take it, but there's a limit to what the iconography can do, and this clearly is one of the cases where iconography alone is insufficient - you need to read the rules.Fortunately nobody so far has complained about the lack of a full-fledged description of "form a federation" just using icons. :)