Completeness of Preferences
Would you like to buy a pack of sugar flavored amazonian soil for 500 dollars?

You can probably answer this question even though you have never heard of this product before. Being able to answer this question, being able to place the newly available consumption alternatives within your ranking is the assumption of completeness.

The same is true if a type of good is replaced. The set of consumption alternatives is changed, but given any two you can still tell which one you prefer.