question about string matching with trailing blanks

In the code below how does Oracle match on field with trailing spaces?

create table a (
 dept char(6) );

 insert into a values ('LABOR ');

 select * from a where dept IN 'LABOR';

Does "dept" match "LABOR"? Is the "rtrim" function necessary? Received on Sat Sep 08 2001 - 10:08:48 CDT