DATA RULES
How CodeMark checks GS1 data
Checks are deterministic and each known field is validated independently.
Primary references
Implementations follow current GS1 public guidance and General Specifications concepts.
Field boundaries
Fixed-length fields consume the defined number of characters; variable fields require FNC1/ASCII 29 or an explicit structured representation.
Limits
Not every sector-specific AI is implemented. Unknown AIs remain visible rather than being guessed.
Printed quality
Symbol verification requires calibrated equipment and is outside this site’s scope.