The NFC attendance solution is an Edusign add-on installed and configured by the Edusign team. Partially update the GPS coordinates, classroom or signing windows of one NFC tag belonging to the authenticated school. Omitted fields remain unchanged. Set classroom to null to clear it. A classroom must already exist in the school. Names are matched without regard to case or accents and saved with their stored spelling. Multiple matching stored spellings are rejected; an administrator must remove the duplicate classroom names. Unsupported properties are ignored; maxDistanceMeters and tagNumber are read-only. A body without any writable field is rejected. Signing windows use boundaries relative to the course start and end. One boundary in each array defines one course-wide access interval, including when both margins are zero. Two boundaries in each array define separate access intervals around the course start and course end. Both arrays must have the same length. Boundaries are exclusive. A pair of zero-minute boundaries disables that interval; updates must leave at least one interval enabled. The response lists only values that actually changed; submitting the current values succeeds with an empty updatedFields array.