The rules define how parameters will be sanitized.
The rules config should be saved serialized for performance reasons. (as for realurl)
The rules can be included/registered for example in the ext_localconf.php like this:
\DMK\MkSanitizedParameters\Rules::addRulesForFrontend(
[
\DMK\MkSanitizedParameters\Rules::DEFAULT_RULES_KEY => [
FILTER_SANITIZE_FULL_SPECIAL_CHARS,
FILTER_SANITIZE_ADD_SLASHES
]
]
);
\DMK\MkSanitizedParameters\Rules::addRulesForBackend(
[
\DMK\MkSanitizedParameters\Rules::DEFAULT_RULES_KEY => [
FILTER_SANITIZE_FULL_SPECIAL_CHARS,
FILTER_SANITIZE_ADD_SLASHES
]
]
);
Note that you can register rules for frontend and backend.