If you look at your 'my games' page you will see an icon to the right of a game when it is possible to send a reminder, but it will not be an available option until your opponent is nearing the end of their 'time-out' period. That is the only time when you will see the icon.
If you do not want to use these move reminders there is an option to turn that feature off when you go to the 'my settings' page.
Originally posted by BaronVonChickenpants Wow, do these still work? I hadn't seen the icon for such a long time I thought the feature was dropped.
To be honest I don't know if it still exists. But if the OP is getting move reminders that would imply that the feature is still functional.
Otherwise, why would he know to ask about it? My first reply explains how it worked as I remember it.
I have never used the feature and have the feature turned off so thought that's why I do not ever see the icon.