[Rilgamon]

I memorized it this way: "do ... end" is a new scope. for, while, etc expand on it.
If your code have variables or functions that run only once during runtime you can put them in a new scope so that they can be removed from memory during the "normal" runtime of your code.

local setting
do
    local result = false
    local function check() 
        return true
    end
    result = check()
    setting = result
end