W. E. Burr 23 MAR 1988 INTRODUCTION The primary purpose of this document is to provide information about X3T9, what it is, how it operates, the standards it has done or is doing, and the information you need to know to follow the discussion in X3T9 or one of its subgroups, to new members and observers. A secondary purpose is to provide something to send to people who inquire about X3T9 or its standards. The third purpose is to help those who do participate to explain to their coworkers and management just what goes on in X3T9. The selection of material is based on the questions I have been asked over the years, as Chair of X3T9.2 and Vice Chair of X3T9, both at meetings and in letters and phone conversations. I expect that the material contained in this document will answer about 75% of the questions I am asked, and, of the remainder, I frequently don't know the answer in any event. A certain amount of opinion is expressed in some sections. It is my personal opinion and does not necessarily reflect the views of the National Bureau of Standards, X3T9, X3 or anyone except myself. Comments, corrections and suggestions for future revisions are welcome. Send them to: Bill Burr National Bureau of Standards Technology A-61 Gaithersburg, MD 20899 (301) 975-2914