<delimited-identifiers /> in orm.xml file seems to be ignored. Even when present, hibernate does not quote identifiers.
Adding <property name="hibernate.globally_quoted_identifiers" value="true" /> in persistence.xml works, however.

The discussions in HHH-9491 Closed and HHH-4649 Closed indicate that Hibernate officially supports this (JPA standard) delimited-identifiers configuration property, but it seems to be ignored, at least in the version bundled in WildFly 16.0.0.

To reproduce, clone https://github.com/oliviercailloux/JavaEE-JPA-Inject-Servlets, deploy on WildFly 16.0.0, observe in the log that the SQL statements use unquoted identifiers. If desired, add a field to the Item class named “from”, redeploy, and see the crash in the log.