Comment 1 for bug 1484613

Easy to confirm with 5.6.

https://www.percona.com/doc/percona-server/5.5/diagnostics/slow_extended.html#log_slow_verbosity
https://www.percona.com/doc/percona-server/5.6/diagnostics/slow_extended.html#log_slow_verbosity

nilnandan@desktop:~/Downloads$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 39
Server version: 5.6.25-73.1-log Percona Server (GPL), Release 73.1, Revision 07b797f

Copyright (c) 2009-2015 Percona LLC and/or its affiliates
Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select @@global.log_slow_verbosity;
+-----------------------------+
| @@global.log_slow_verbosity |
+-----------------------------+
| |
+-----------------------------+
1 row in set (0.00 sec)

mysql> SET global log_slow_verbosity=standard;
Query OK, 0 rows affected (0.01 sec)

mysql> select @@global.log_slow_verbosity;
+-----------------------------+
| @@global.log_slow_verbosity |
+-----------------------------+
| microtime,query_plan |
+-----------------------------+
1 row in set (0.00 sec)