sh:message is not limited when used with SPARQL Constraint.

[afs]

https://www.w3.org/TR/shacl12-sparql/#sparql-constraints-syntax does not mention the condition that sh:message must be unique for a given language.

If sh:message is on a shape, this text applies:
https://www.w3.org/TR/shacl12-core/#message

"A shape should not have more than one value for sh:message with the same language tag."

But what about having two sh:message xsd:string?

(from apache/jena#3817)