Since FORTRAN-77 does not allow for dynamic memory management most large FORTRAN projects invoke some sort of memory manager like the CERN zebra or DESY BOS packages. The idea is to steer the user away from static common blocks so that it becomes harder to corrupt the data in memory and supposedly easier for the user to interface to the data. The usage of the BOS package does not really save on memory usage since it initializes a huge array (IW), in which all the data manipulation is to take place. Couple this large IW array with the fact that the first thing most people do is copy their BOS banks into static arrays kept in common blocks, we really are not accomplishing much by using BOS. Be that as it may. The user is needs to know how to get access to the CLAS data, either RAW or reconstructed. Since this will be done through BOS banks the user should know how find this information. The use of ASCII files that describe each BOS bank provides a self documenting mechanism. These files are named ddl files for d ata d escriptor l anguage and their format was taken from an H1 BOS utility software package.