I would be fully in favour of this RFC, but there is 1 hurdle which cant be ignored.
What should the PHP naming convention be for these? Without deciding on what it should be we would be creating a new issue of mix-mash of uppercase, lowercase and camelcase classes for example Few examples - DateTime is documented as Camelcase - https://www.php.net/manual/en/class.datetime.php - PDO is documented as uppercase - https://www.php.net/manual/en/class.pdo.php - mysqli is documentated as lowercase - https://www.php.net/manual/en/set.mysqlinfo.php - ArrayAccess is documented as camelcase - https://www.php.net/manual/en/class.arrayaccess.php PHP mixing case of definitions, at least with current system, users can choose their preferred convention and it will work. If we change to be case sensitive, we risk introducing a giant headache for devs, as they need to remember what different casing each different builtin class is. It will become a the new `($haystack, $needle)` - `($needle, $haystack)` problem, and won't gain love from the community. On Wed, 17 Jun 2026 at 01:03, Jorg Sowa <[email protected]> wrote: > Hello internals, > I would like to revive the discussion about fully case-sensitive PHP. I > have collected the points raised in previous discussions, and browsed all > affected language features and functionalities. > > I still need to perform the impact analysis and the performance > benchmarks. I will add them to the RFC and inform in the thread when I > complete it. > > RFC: https://wiki.php.net/rfc/case_sensitive_php > > Kind regards, > Jorg >
