Just so I understand: Is it important for you to actually extract the city entity with DIETClassifier? If it’s enough to just extract it with RegexEntityExtractor, then I wouldn’t bother annotating it in many intent examples (the docs say 2 examples are enough for the regex extractor) – and you should be able to safely ignore any mistakes that DIET makes regarding this entity. Note: If this is your only entity, you could even turn of entity extraction in DIET altogether.