function-orchestrator code can be found at https://gerrit.wikimedia.org/g/mediawiki/services/function-orchestrator. Built-in functions have argument characterizations created by calls to builtinReferences.set, in builtins.js.
The argument characterization for Z813 has been updated for typed lists (*), and it should no longer accept Z10s, but the existing Z10 test cases are still passing. These cases should fail with a validation error.
This change will also benefit other list functions when their argument characterizations are updated.
(*) See also https://gerrit.wikimedia.org/r/c/mediawiki/services/function-orchestrator/+/748329