SHOW [{GLOBAL | SESSION}] VARIABLES [WHERE variable_name='xxx' | LIKE 'pattern']

It returns the current values of a few server-wide variables. Also, support for GLOBAL and SESSION clauses was added.

mysql> SHOW GLOBAL VARIABLES;
+--------------------------+-----------+
| Variable_name            | Value     |
+--------------------------+-----------+
| autocommit               | 1         |
| collation_connection     | libc_ci   |
| query_log_format         | sphinxql  |
| log_level                | info      |
| max_allowed_packet       | 134217728 |
| character_set_client     | utf8      |
| character_set_connection | utf8      |
| grouping_in_utc          | 0         |
| last_insert_id           | 123, 200  |
+--------------------------+-----------+
9 rows in set (0.00 sec)

Support for WHERE variable_name clause was added, to help certain connectors.

SHOW COLLATION

This is currently a placeholder query that does nothing and reports success. That is in order to keep compatibility with frameworks and connectors that automatically execute this statement.

mysql> SHOW COLLATION;
Query OK, 0 rows affected (0.00 sec)