From a few pages back:
The HQ version of Tassets has Det +8 and SS +16 already included. So, an almost fully melded belt could add something like Acc 9 + 6 = +15 (Tier IV + Tier III), Crit 9 + 6 = +15 (Tier IV + Tier III) and Det +4 (Tier III). You'd be one shy of cap for Acc and Crit. Doing it this way you'd want to meld the Tier IV first, which is why you see Crit or Acc melded first, depending on which is more expensive on your server. Then the tier III in order of expense.