Nope, it's not another suggestion post about flame tanks.. Sorry. But I've searched the wiki about researching in Hammer Editor, basicly, to have a map with Medium tanks for example. And I wondered, what entity/thing do I need to place/change to change research? Doing a 'lil special map, and the special research is needed for it.. ove:
You'll need to look in the research_items.txt file in empires/scripts to figure out the name. You also need to use unresearch for the standard researched items to be removed.