| Data Flags |
| Flag |
Description |
| N/A |
Unqualified |
| < |
Below detection limit |
| > |
In excess of quoted value |
| A |
Taxonomic flag for affinis (aff.) |
| B |
Beginning of CTD Down/Up Cast |
| C |
Taxonomic flag for confer (cf.) |
| D |
Thermometric depth |
| E |
End of CTD Down/Up Cast |
| G |
Non-taxonomic biological characteristic uncertainty |
| H |
Extrapolated value |
| I |
Taxonomic flag for single species (sp.) |
| K |
Improbable value - unknown quality control source |
| L |
Improbable value - originator's quality control |
| M |
Improbable value - BODC quality control |
| N |
Null value |
| O |
Improbable value - user quality control |
| P |
Trace/calm |
| Q |
Indeterminate |
| R |
Replacement value |
| S |
Estimated value |
| T |
Interpolated value |
| U |
Uncalibrated |
| W |
Control value |
| X |
Excessive difference |