False Path Definition

Hi,
After doing quite a bit of research on false paths, I still do not have the concept clear in my head. Can somebody advise if the below example would be considered a false path?

Process 1:
If rising edge (66MHz_clk) then
alarm_signal <= '1'
end

Process 2:
If rising edge (10MHz_clk) then
if alarm_signal = '1' then
do something
end


I have something similar in a current design and I am recieving timing warnings. I later set the paths between both clocks (in both directions) as a false path and it has cleared up any timing issues.

Is this ok to do?

If possible, can someone please describe when and where it is ok to make a false path, e.g. what the circumstances must be.


Thanks very much for any advise.

Ardni