Larry - The numbers were used during the filing of entries from other documents (such as unit musters) while the clerks at the U.S. War Department were filing information in individual "Compiled Service Records." They no longer have any meaning, since the project was finished many years ago. This is not to say that the War Dept. ever really "finished" the project, since microfilm series M347 has 442 rolls of "Unfiled Papers & Slips Belonging in Confederate Compiled Service Records." Hope this helps.