safe state machines

I apologize that this comes late, but I've finally found the printed Altera booklet where this information appears. It's named "qil51006-5.0.0" and dated May 2005. In chapter 5 ("Design Recommendations for Altera Devices"), in the "State Machines" sections, the second bullet says:

--- Quote Start ---

Assign a default clause or statement to direct the state machine if it accidentally reaches an unused state.

--- Quote End ---

It doesn't say anything about minimizing such clauses automatically in this section, and nothing about the safe state machine option.