A line-level referenced document is not an invoice line object identifier
On an invoice line, `Additional referenced document` is admitted only with type code 130 — the invoice line object identifier (BT-128).
Only the issuer holds this value: Factlint reports it and never fabricates it. Test your invoice to find out whether it is affected.
The message your validator prints
Copied verbatim from the sealed artefact: this is the exact sentence the check prints when this rule fails.
ciiElement Additional referenced document can only be used for Invoice line object.
ublElement Document reference can only be used for Invoice line object
Quoted from schematron-xrechnung 3.0.2, licensed under Apache-2.0.
Common searches around this code
These phrases mirror what an integrator searches for: code, syntax, rule, business field and correction.
Test your file with this error in mind
Upload the invoice involved: the report will say whether this code appears, where it appears in the document, and whether Factlint can only report it or also fix it.
To automate this check in an ERP flow, call the validation API and link every returned code to its public page.
Why this error happens
The location exists in CII syntax but EN 16931 gives it a single use. Attaching a file or a delivery note there produces a document the recipient will ignore: the data is written, it is not read.
How to fix it
Move the reference to document level, where EN 16931 expects it. Factlint does not move it: nothing says what it was meant for.
XML correction example
<ram:AdditionalReferencedDocument><ram:TypeCode>916</ram:TypeCode>
<ram:AdditionalReferencedDocument><ram:TypeCode>130</ram:TypeCode>