Check variable-length OCR completeness beyond valid syntax

When parsing variable-length identifiers from tight RF-DETR crops with PaddleOCR, validate recognition completeness separately from confidence, syntax and candidate uniqueness. Omitting characters may produce another legal whole token, so these gates can pass even when the crop retains the full number. Include stacked and multiline identifiers with preserved prefixes and leading zeros in evaluation, and count accepted partial reads separately from nulls and wrong-region detections. Complete-box detector metrics cannot substitute for this check. Additional visual or layout evidence may support an abstention gate, but its effectiveness must be evaluated rather than assumed.

Applies when: A crop parser accepts fleet or unit identifiers without a fixed length or check digit. Keywords: RFDETR PaddleOCR trailer crop parser completeness confidence partial identifiers stacked