+The library's initial logging level is controlled by the
+\c LIBBABELTRACE2_INIT_LOG_LEVEL environment variable. If this
+environment variable is not set at library load time, the library's
+initial logging level is #BT_LOGGING_LEVEL_NONE. See
+\ref api-fund-logging to learn more.
+
+Set libbabeltrace2's current logging level with
+bt_logging_set_global_level().
+
+\anchor api-logging-extra-lib bt_logging_set_global_level() only
+controls <strong>libbabeltrace2</strong>'s logging level; it does \em
+not control the logging level of:
+
+- Individual \bt_p_comp: bt_graph_add_source_component(),
+ bt_graph_add_source_component_with_initialize_method_data(),
+ bt_graph_add_filter_component(),
+ bt_graph_add_filter_component_with_initialize_method_data(),
+ bt_graph_add_sink_component(), and
+ bt_graph_add_sink_component_with_initialize_method_data() control
+ this.
+
+- A \ref api-qexec "query operation":
+ bt_query_executor_set_logging_level() controls this.
+
+- The bt_get_greatest_operative_mip_version() operation: its
+ \bt_p{logging_level} parameter controls this.
+
+As of \bt_name_version_min_maj, there's no module-specific logging level
+control: bt_logging_set_global_level() sets the logging level of all the
+library's modules.
+
+libbabeltrace2 writes its logging statements to the standard error
+stream. A logging line looks like this:
+
+@code{.unparsed}
+05-11 00:58:03.691 23402 23402 D VALUES bt_value_destroy@values.c:498 Destroying value: addr=0xb9c3eb0
+@endcode