+/* Logging importance levels.
+ *
+ * The following log levels, in descending order of importance, are enabled by
+ * default:
+ *
+ * - EMER: Not currently used.
+ *
+ * - ERR: A high-level operation or a subsystem failed. Attention is
+ * warranted.
+ *
+ * - WARN: A low-level operation failed, but higher-level subsystems may be
+ * able to recover.
+ *
+ * - INFO: Information that may be useful in retrospect when investigating
+ * a problem.
+ *
+ * The lowest log level is not enabled by default:
+ *
+ * - DBG: Information useful only to someone with intricate knowledge of the
+ * system, or that would commonly cause too-voluminous log output.
+ */