Since the first SEG-Y standard was published, many companies dealing with seismic data have produced variants of the SEG-Y standard which have run contrary to the aims of defining a standard for universal interchange, thus generally causing confusion and delay when data received by a company in expected SEG-Y format turns out to be a variant of that format. Initially, many of these derived from the fact that the format was based on the de facto standard of using IBM computers for digital processing where character data was coded in EBCDIC and number data in IBM Floating Point, whereas processing systems in use quickly evolved based on ASCII character and IEEE number representations.