The JPA spec specifically says: <quote> Either positional or named parameters may be used. Positional and named parameters must not be mixed in a single query. </quote> I was thinking about how it does not make sense to mix these in a query (its confusing) and went looking to see what, if anything, the spec had to say on the subject. Which is when I found that passage. Currently we do not validate this one way or the other. But I think we ought to start. The only real question is whether to make this an exception all the time, or just when strict-JPA-compliance is requested. Personally I vote for always disallowing this (like I said, I find it confusing), but would like to get other's thoughts.