In the field, finds are often bagged and numbered as field specimens before they ever receive a permanent catalogNumber. The fieldSpecimenNumber preserves that original field identifier so you can trace an artifact back to the bag it came in. It is optional, since some records are created directly in the lab without a separate FS number. Keeping it on the artifact lets you reconcile field paperwork against the final catalog during washing, sorting, and cataloging.
Technical section
Data model, API, and internals — visible to developers.