Debug information is output from a point-of-scale scanner by disguising it as one or more product identifiers (e.g., Global Trade Item Numbers, or GTINs). Generation of such “faux GTINs” to convey the debug information can be activated by presenting a special machine readable code to the scanner. Repetitive patterns in the debug information are desirably varied to avoid triggering duplicate detection logic in the scanner, which might otherwise suppress outputting of such repetitive information.