What does the term "Crossover" mean for then option "Allow Crossover" on an OCR?

Problem:

What does the term "Crossover" mean for then option "Allow Crossover" on an OCR? 

Likely Cause(s):

n/a 

Resolution:

The "Allow Crossover" option is used when you are have a Fixed schedule setup for a particular visit (meaning that invitees and bidders are segregated onto separate schedules), allow crossover means that if you run out of one type of student, you can fill in the available schedule slots with the other type of person.
 
Example: fixed, 10 invite slots, 10 bid slots, 2 schedules.  you have 10 invitees and 2 alternates from the employer.  Only 9 students bid.  Allow crossover permits alternate #1 to fill the available open slot.  Same is true if you have tons of bidders and not enough invitees from the employer. 

Program Setting:

 n/a