Different ways of passing procedure's paramters

Question

Hi,
In the following example, I am calling the procedure p_test in different ways.
I understood from reading examples, that we can pass parameters using the syntaxe : " Name of the parameters => Value".
But I did not find anything official about it.
I'm just looking for Oracle Documentation where it is explained the syntaxe " Name of the parameters => Value".
CREATE OR REPLACE procedure test_call
is
procedure p_test(I_FIRST IN NUMBER DEFAULT 1, I_SECOND IN NUMBER DEFAULT 2 )
is
begin
dbms_output.put_line ('-----------------');
dbms_output.put_line ('FIRST:'||I_FIRST);
dbms_output.put_line ('SECOND:'||I_SECOND);
end;
begin
p_test(10,11);
p_test(10);
p_test();
p_test(I_FIRST => 100);
p_test(I_SECOND => 200);
p_test(I_SECOND => 2000, I_FIRST => 1000);
exception
when others then
ks_Error.log();
end;
/

Answer 1

note that the => is illegal in sql in 10g and before
select f(x=>1) from dual;
ERROR at line 1:
ORA-00907: missing right parenthesisbut it will probably be possible in 11g