You will also see movements marked 'unadjusted' which means they were not tested for accuracy in three, five, or six different position.

A watch adjusted to three position might keep better time by 2 seconds a day, but they are not worth the extra cost if all you are going to do is keep time. If you are running a railroad you would need one adjusted to six positions, so sometime you will see watches advertised as 'railroad approved'.