While writing API tests for mod-kb-ebsco we found some inconsistency in when HTTP status code 422 is used vs HTTP status code 400.
POST /eholdings/titles with an invalid name returns an HTTP status code 422
PUT /eholdings/resources with an invalid name returns an HTTP status code 400
This could be due to returning error information as a passthrough from rm api vs directly detecting the error in mod-kb-ebsco.
Would be helpful to review status codes that are returned to be sure they are consistent and predictable.