I could not find anything stating in the spec how the limits are to be used for the deviation alarms.
There was an example where the low was negative, so I do assume that both high and highhigh shall be positive and low and lowlow shall be negative (for all deviation alarms). Would make sense to state this in the spec. [As alternative, low could be the distance to the lower as positive value, so the minus would be implicitly].

I also did not find a statement that at least highhighlimit >= highLimit>=lowlimit>=lowlowlimit (for all limit alarms)