ABSTRACT
When a document is revised its status changes to signify that it is no longer identical to the original version. This status may be indicated by date, by letter or by number or may be a combination of issue and revision. Every change to a document should revise the revision index. Issue 1 may denote the original version. On changing the document an incremental change to the revision index is made so that the new version is now Issue 2 or issue 1.1 depending on the convention adopted.
