300mm f/2.8 NON IS - Lens Switches - HELP!

I've just purchased a used 300mm f/2.8 non IS and am very happy with the performance thus far.

My problem is reasonably simple, It did not come with a user manual and I cannot locate one online. As a result I'm not 100% on what all the operation switches on the lens represent.

1) Distance - I have no problems with that one

2) AF- M - Again no problems

3) (((.))) - You can either select this symbol or not? No idea what it is?

4) M.Focus Speed - options are 1,2 or 3 - not sure if it's maximum focus speed and 3 is the fastest? I'm not sure why you'd want to vary that though so maybe it means something else?

All help greatly appreciated!

3) It turns the focus-recall beep on/off and also is the switch to set the focus recall point. There is metal ring around the lens that you can turn to do the focus recall.

4) You can easily try this. It's the manual focus speed. Set the lens to manual focus and then turn the manual focus ring and watch the focal length dial. Change the speed and repeat. It'll become obvious very quickly how it works. If you only use auto-focus, it won't affect anything.