When a large amount of charted information on a chart is updated and revised, the chart is published as its "new edition" with the same chart number as its previous one, and a new publication date is given to the new edition of the chart. On publication of a new edition, its previous edition of the chart with the same chart number is withdrawn, which cannot be used for navigation any more.
The publication date of each chart is shown at the center of the lowest margin of the chart. You can also confirm the “publication date” of each existing Japanese chart by visiting the JHA website: List of Charts and Publications
- New Chart (NC)
- The first publication of a chart which will either embrace an area not previously charted to the scale shown or embrace an area different from any other existing charts. A new chart number, a new chart title and a new publication date are given to the new chart.
- New Edition (NE)
- A new issue of an existing chart, embodying large corrections that have become so extensive or of such importance to navigation as to render all previous printings (previous editions) obsolete. Its chart number and the chart title remain unchanged, but a new publication date will be given. On publication of a new edition, its previous edition is withdrawn and cannot be used for navigation any more.
- Withdrawn or Cancelled Chart
- A chart withdrawn by publishing its new edition bearing the same chart number. Also a chart withdrawn independently because of no need to be published any more. The withdrawn charts cannot be used for navigation since any corrections and blocks for these charts will be no more issued in Notices to Mariners. Charts to be withdrawn is announced in weekly NtM bulletins and the JCG website: Notices to Mariners
- Reprint
- A new print of the current edition of a chart incorporating no amendments of navigational significance other than those previously promulgated in Notice to Mariners (if any). It may, however, contain amendments from other sources provided they are not essential to navigation. Previous printings of the current edition of the chart always remain in force and can be used for navigation as long as they are kept up-to-date by Notices to Mariners.
- Out of Print
- A chart which is no more available and will not be supplied for future but can be used for navigation as long as it is kept up-to-date by Notices to Mariners.
