We have modified all of our machining so we never need 6th face operations. The only time we will need it is when there is line bore on both sides with different patterns. 

However, on every nest, there are 6th face ops. 

We use a T+G (or lock dado construction as its called in the program) and when our parts nest, it forces the tongue to 6th face about 1/3-1/2 of the time.

See Image. The bore holes in green to the right of the tongue cut are through holes. why wont it process the part so its all 5th face?

On some other parts, its the groove (or dado) pilot holes.

We have toyed with various settings to get it to truely force all ops to the 5th face, but some just dont want to comply.

oh and a seperate question: 

Why do some of our parts have an * next to the number? theres no 6th face operation on that whole sheet.