I have tried 3DPBOARD and 3DPRINT on the ID Code for the conference registration and both were rejected. The announcement said:

If you are interested in attending, you can get 10% off by using our special “3DPRINT” promo code at checkout. Will you be at this year’s show? Be sure to let us know in the Inside 3D Printing forum on 3DPB.com.

I tried this on the Vertical Track Pass and it was rejected.