A new issue of an existing chart containing amendments essential to navigation. These amendments are in addition to those issued in Notices to Mariners and make existing editions of the chart obsolete.
The first publication of a Canadian chart, either for an area not previously charted to the scale shown, or for an area different from any existing Canadian chart.
A new print of the current edition of a chart incorporating no amendments of navigational significance other than those previously published in Notices to Mariners. Previous printings of the current edition always remain in force.