Divorced Parents Disclosure?

Spent time this weekend looking at college websites, and noted that
many ask for something called the "divorced parents disclosure" (I may
have the lingo wrong) in addition to the FAFSA and Profile.  What is
this?  Will the calculators at Finaid.org and elsewhere allow us to
calculate expected family contribution including this form?  How many
colleges require this form?  Does his mean some colleges expect
contributions from FOUR adults:  two natural parents plus two
step-parents??  Thanks for any input.