code: private void checkNonCoreArtifactId(Model model) throws EnforcerRuleException
      {
          String artifactId = model.getArtifactId();
          for (String prefix : CORE_ARTIFACT_ID_PREFIXES) {
              if (artifactId.startsWith(prefix)) {
                  throw new EnforcerRuleException("The [%s] artifact id prefix is reserved for XWiki Core Committers.");
              }
          }
      }
docs: Make sure that non core artifacts don't use reserved artifact prefixes.