Hi I've just bought a Makita Ls1013 sliding mitre saw. Supplied with it
is something called a "Kerf Block" which is semi circular and
supposedly screws just behind the fence in the middle, in line with the
blade.

The manual is complete gobblydegook on this section, except from where
to put it.

Could someone who has got a LS1013 tell me what is this for and when I
would use it?

Also worryingly if the blade is pushed right towards the fence it will
neatly slice the "Kerf block" in half!!!!

I've tried tinternet to no avail.

Thanks in advance

Graham