The permitted warning types can be configured via the allow option.
The value is a list of whitespace-delimited warning types that you
want to be able to disable. See perllexwarn for a list
of possible warning types. An example of this customization:
allow = uninitialized once
If a true value is specified for the
allow_with_category_restriction option, then any no warnings
that restricts the set of warnings that are turned off will pass.
allow_with_category_restriction = 1