EDIT: for context
There's a difference between certificates distributed with the OS and certificates added to the OS by a user. Right now Firefox ignores both.
This change ONLY picks up the certificates added to the OS by a user. Firefox will continue to ignore the certificates included with the OS store by default.
Recognition means that web browsers are required to ensure support and interoperability for the QWAC for the sole purpose of displaying identity data in a user-friendly manner. *Recognition of QWACs implies that browsers shouldn't question the origin, integrity or data in the certificate*.
However, the requirement to recognise QWACs does not affect browser security policies and leaves web browsers free to preserve their own procedures and criteria for encryption and authentication of *other certificates*.
https://ec.europa.eu/commission/presscorner/detail/en/QANDA_...