Scheduled reminder "limit to" options missing

The current text for the "Recipients" drop down on the scheduled reminder talks about limit to and also include. This field doesnt appear on the page.

I'm not sure what the functionality is supposed to be here - but I know that from a user perspective the ability to have a scheduled reminder go to a different person then the subject of the activity, membership or event would be useful.

If you select group does that mean only those who are the subject of the activity membership or event AND are in the group will be emailed or is it an OR.

Let me know and I could write some better text.