Labelproof/rules
will failST-04structure

Long text is cut off at the end of a ZPL field

This field carries more than the 3072 characters ^FD accepts. The excess is lost.

Split the content across several fields.

A label that trips it
^XA^FO50,50^FDXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
… (3093 characters in total)
Rendered example
What the check looks for

^FD field data longer than the documented 3072-character limit.

What Labelproof says about it2 findings · ST-04 highlighted
will failLY-02^XA · offset 0 · label 1

Neither ^PW nor ^LL is set. Both fall back to a value stored in the individual printer, not to a value in the spec — so the same ZPL prints differently on two printers of the same model.

Set ^PW and ^LL explicitly in every format.

the rule on this page
will failST-04^FD · offset 3 · label 1

This field carries more than the 3072 characters ^FD accepts. The excess is lost.

Split the content across several fields.

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