EXP Cap?

This guy explains exactly. Although, this was in Jan 2013 so it was during the 3!6!9! event

 Spoiler

" I am training at 16.5x exp in GMS Maplestory using Museum Master 2x EXP coupon buff, Cash Shop 2x EXP, 2x EXP event, Elven Blessing (EXP link skill), 3!6!9! Event (bonus EXP on every third monster) and Pendant of Spirit.

Too bad I didn't have the EXP Accumulation Potion."

Except that's not 16x. The problem is the Elven Blessing, 3/6/9 event and Pendant are all separate lines of EXP. They aren't actually multipliers. You can clearly notice this when he's killing Aliens and he's only getting 12,000 EXP, which is only 4x multiplier.

The old "EXP Cap" was when you achieved a multiplier of 10.6x (or whatever the cap was) from the base EXP value, not in total.