Navigation, Orientation, Information
As a Community needs orientation on joining a new World, as they need guidance and Informations it is necessary to provide.
I didn't see any "signs" of Signs, Maps and Information screening yet but here are some of my thoughts.
First off, Sign boards from Wood and Metal and later on TV-Screens and such to lead the way to important buildings like the Town Hall and Market. Also to give sense to Roads and Districts (Market, Housing, Governmental, Workshops,...)
Next up, Maps. A map can show you various informations on the World from inside the Game. Whether it is just locations you may also switch to geographical maps, topographical maps, area maps (forest, see, river, dessert, wasteland, swamp..), pollution map..
(May also be interesting in Classes having interactive maps to work with to learn how to read them and understand them instead of taking a globe or atlas or google maps.. xD)
Than we have the informations, Town Halls can have bulletin-boards, shops can have billboards to show off offers and sales, Workshops can offer work (quest), and so on.. Those boards can also either be wooden, metal or later on Screens. They also have to be interactive in some form (Accepting Quests, Scrolling, ...)
So, Media in general for what ever the community is going to... from information to adverts and other stuff.
To the eco part. These things have to be crafted, sold and build up. They have to be somehow protected and licensed in order to allow safety from manipulation.
If I forgot something here.. maybe you can find it? :D