The number of copies of this book are unknown but because of the magic marker lines, no two are exactly the same.Steve Heller on internet describes tenghe original Selectric Composer, announced in 1966, required text to be typed twice. On the first pass, the machine would automatically measure the length of the line, providing the operator with a color+number (i.e. green-2) combination to be noted in the right margin. When the operator finished all lines of the document, they would put a clean sheet of specially coated paper into the machine and engage the justification lever. This time, prior to typing each line of text, the operator would turn a color dial to the noted color, and another dial to the noted number. Once the dials were set, the operator would begin typing the text. While typing, the Composer would insert incremental amounts of additional space between words such that the line would always be flush on the right margin. Errors could not be corrected, and when they occurred, the operator would simply space down a few lines and retype the line. In those days, cut and paste literally meant cut and paste. The completed copy would be cut, removing any erroneous lines, and pasted onto a layout sheet for later processing. -- Source of annotation: Marvin or Ruth Sackner.