Cool idea, I hope it reaches some kind of critical mass! One question though: what does the available/unavailable status mean? I'm unclear what the difference

Cool idea, I hope it reaches some kind of critical mass! One question though: what does the available/unavailable status mean? I'm unclear what the difference is, especially since anyone who would fill out a profile here is available in some form. You may want to add some clarification, I wasn't sure what to use that for.