Added comments about New relic High Security mode

src/Monolog/Handler/NewRelicHandler.php

@@ -14,9 +14,11 @@ namespace Monolog\Handler;
 use Monolog\Logger;
 
 /**
- * Class to record a log on a NewRelic application
- *
+ * Class to record a log on a NewRelic application.
+ * Enabling New Relic High Security mode may prevent capture of useful information.
+ * 
  * @see https://docs.newrelic.com/docs/agents/php-agent
+ * @see https://docs.newrelic.com/docs/accounts-partnerships/accounts/security/high-security
  */
 class NewRelicHandler extends AbstractProcessingHandler
 {