EDU refers to export_descr_units.txt (sorry, we use abbreviations for common text files). "Dictionary" is quite easy to find if you look in EDU - each unit has a "dictionary" entry. This entry is used in other places, notably to check for a unit card .tga and an info pic .tga. If the dictionary entry changes, you'll need to change the corresponding names of the unit card and unit info pic .tgas.