DATA_PATHS is fundamental to several routines including YODAT. The routine should return a string array with all the directories where there are Yohkoh reformatted data. The routine is site specific since each institute organizes the data slightly differently. A common practice is to use DATA_PATHS2 to get the standard data directories, and then append the specialized data directories. See the sample DATA_PATHS program in the `site' branch of the Yohkoh software.