Adding a little more, these lines show the status of Favorites List Quick Keys and System Quick Keys.
"F" stands for Favorites List Quick Key ("FLQK"). The position behind the "F" is the first digit of the FLQK, noting you can have FLQKs 00-99. If you have a FLQK 10 or higher, then you would see "F1", "F2" and so on up to "F9".
The remaining places are for the second digit of the FLQK. If no FLQKs are assigned, as noted above, you see dashes. If the FLQK is On, then the appropriate digit appears. If the FLQK is Off, then you'll see an asterisk (*).
The "S" is for System Quick Keys ("SQK"). This line applies to systems associated with the FL actively scanned. The same general scheme (first and second digits of the SQK) apply.
It is a little daunting at first, but once you assign FLQKs and SQKs and what the scanner for a little while, it becomes more obvious.