https://www.php.net/manual/en/function.mb-strlen.php mentions in the error section that a warning may be raised with an invalid encoding. But that's not what happens: https://3v4l.org/E9s0i. A ValueError is raised instead.
For some other pages, the error condition for $encoding is also not specified. I only had a quick look instead of composing a list of all the pages that lack one.
https://www.php.net/manual/en/function.mb-strlen.php mentions in the error section that a warning may be raised with an invalid encoding. But that's not what happens: https://3v4l.org/E9s0i. A ValueError is raised instead.
For some other pages, the error condition for $encoding is also not specified. I only had a quick look instead of composing a list of all the pages that lack one.