Here's a short explanation of
the configuration directives.
intl.default_localestring
The locale that will be used in intl functions when none is specified
(either by omitting the corresponding argument or by passing
NULL). These are ICU locales, not system locales.
The built-in ICU locales and their data can be explored at
» https://icu4c-demos.unicode.org/icu-bin/locexp.
The default value is empty, which forces the usage of ICU's default
locale. Once set, the ini setting cannot be reset to this default value.
It is not recommended that this default be relied on, as its effective
value depends on the server's environment.
intl.error_levelint
The type of the error messages generated when an error occurs in ICU
functions. This is a
PHP error level, such as
E_WARNING. It can be set to 0
in order to inhibit the messages. This does not affect the return values
indicating error or the values returned by
intl_get_error_code or by the class specific
methods for retrieving error codes and messages.
The default value is 0.
intl.use_exceptionsint
If set to true, an exception will be raised whenever an error occurs in
an intl function. The exception will be of type
IntlException. This is possibly in addition to the
error message generated due to intl.error_level.