From my understanding when I impl-ed it in TomEE it was for existing extension registering beans from jars without beans.xml. If these jars are now auto discovered the app can be broken.

Extension disqualifies a jar as 'implicit bean archive'? -------------------------------------------------------- Key: CDI-579 URL: https://issues.jboss.org/browse/CDI-579 Project: CDI Specification Issues Issue Type: Bug Reporter: Mark Struberg Priority: Minor The bean-discovery-wording is a bit odd. This has been in since CDI-1.1 {code} An archive which: • contains a beans.xml file with the bean-discovery-mode of none, or, • contains an extension and no beans.xml file is not a bean archive. is not a bean archive. {code} That means even if you have an @ApplicationScoped MyService class in a jar which has a single CDI Extension then this MyServices will *not* get picked up as CDI bean? At least according to this wording? Feels mega-weird to me and might conflict with the implicit beans archive definition a few lines below. I'm pretty sure in OWB we will pick those beans up. How does Weld behave?