This flag explains why there is no appropriate value in the corresponding date data item, Date of Regional Lymph Node Dissection [682]. This data item is required for CoC-accredited facilities as of cases diagnosed 01/01/2018 and later.

As part of an initiative to standardize date fields, date flag fields were introduced to accommodate non-date information that had previously been transmitted in date fields.

10	No information whatsoever can be inferred from this exceptional value (that is, unknown if any regional lymph node dissection was performed)
11	No proper value is applicable in this context (for example, no regional lymph node dissection was performed; autopsy only cases)
12	A proper value is applicable but not known. This event occurred, but the date is unknown (for example, regional lymph node dissection was performed but date is unknown)
Blank	A valid date value is provided in item Date of Regional Lymph Node Dissection [682]. Case was diagnosed prior to January 1, 2018.