One file. Try deleting all the entries in a copied text file and entering your own. Or download mine and customize it from there. Also note, you don't even NEED a text reference file if you plan to directly enter all your text information into the actual files themselves. For instance, instead of referencing city names (TXT_KEY_CITY_CHICAGO) you can just type in city names into the city list directly (Chicago) -- along with leader names and other things. The main purpose of a text reference file is for multiple languages, imo. ... wow that would be a long response. But basically you want to find an entry within the unit list that you plan to make your unit replace. Copy the entire Unit's reference -- then change its type to your type (not the class). Afterwards you want to reference the UU in the Civilizations xml info files.