The depthCmbd field captures vertical provenience as a depth in centimeters below the excavation's established datum point. Recording depth below datum rather than below surface gives a consistent reference across an uneven site. The field is optional but is standard for piece-plotted finds. Stored as a decimal, it preserves the centimeter-level precision archaeologists rely on to correlate finds with stratigraphic layers and reconstruct the sequence in which objects were deposited.
Technical section
Data model, API, and internals — visible to developers.