Question came up regarding the order of deductions from NQDCP and 401(k). Since 401(k) must use 415( c)(3) as the definition of comp, shouldn't the 401(k) deferral percentage now always be applied after NQDCP deferrals are deducted?

Example - gross salary $150,000, 10% 401(k) deferral, 10% NQDCP deferral
Deferrals - $15,000 to NQDCP and $13,500 to 401(k)

If I recall correctly, all of the 415©(3) safe harbor definitions exclude contributions to a NQDC plan, so the 401(k) deferrals would be based on the net, as you suggested.

But if you have to fill up the 401(k) first, wouldn't you use the gross?

Also 1.415©-2©(1) excludes employer contributions to NQDC plans from compensation, not salary deferrals. I would think you'd use the gross salary and thus disregard NQDC salary deferrals.