RNC Charts are available as Source Editions, Raster Editions or NoticeToMariner Editions.
	Each RNC Chart has a Print Date, an NTM Revision Date and various Cleared Dates.
Source Editions are made available when a lithographic new edition of the chart is published.
-	The Print Date is the same as the chart's lithographic new edition print date.
Raster Editions are generally made available when a revised documentation file is republished from the same Source Edition.
NTM Editions are generally made available when a Notice to Mariner correction as been applied to the RNC chart.
-	The NTM Revision Date is the date through which the RNC chart has been corrected or cleared with Notice to Mariners corrections at the time the RNC chart is made available.
Cleared Dates can be determined for each RNC Chart.
-	Clear Dates are based on the examination of Notice to Mariners published by NGA and USCG, and the application to the RNC Charts of critical corrections from these publications.
-	If no critical corrections have been published since the RNC Chart was last made available, then the RNC Chart's Cleared Date is the date of the last examined Notice To Mariners publication.
-	If there has been a critical correction published since the RNC Chart was last made available, then the RNC Chart's Cleared Date is the date of the last Notice To Mariners published prior to the publication of the critical correction.
-	If the RNC Chart is made available directly after the application of a critical correction, then the RNC Chart's Cleared Date is the date of the Notice To Mariners publication that included the correction.