Format changing instructions don't work for me.

None of these format changing instructions yields different result, i always get standard table based result, any idea why ?

SELECT /*csv*/ * FROM my_table;

SELECT /*xml*/ * FROM my_table;

SELECT /*html*/ * FROM my_table;

SELECT /*delimited*/ * FROM my_table;

SELECT /*insert*/ * FROM my_table;

SELECT /*loader*/ * FROM my_table;

SELECT /*fixed*/ * FROM my_table;

SELECT /*text*/ * FROM my_table;

Oracle SQL Developer 4.1.5.21

Build MAIN-21.78