Photographs of non-portable archaeological features — a hearth, a posthole, a wall — attach to that context through the featureId on the PhotoRecord. This optional link gathers every image of a single feature in one place, which matters because features cannot be lifted and stored like artifacts, so their photographs are often the primary record of them. The field is indexed for quick lookup, and if the feature is deleted the photo remains while its featureId is set to empty.
Technical section
Data model, API, and internals — visible to developers.