For a tier-1, do they call every former employer you list or just select some?
They will certainly contact your current employer… sounds like there is someone you’d rather not have them contact 
They will contact them usually via mail with a form to complete with information regarding your employment there.
sure, but not my current employer.
Too bad.
If you don’t want your current employer contacted, what would come to light when they are contacted?
nothing on current employer, just termination on a prior employer. Nothing really bad, just a manager who seems to always look for a reason to get rid of me. Anytime I took a stand against his opinion, he would try to find some error or what he perceived as an error in my work just to say he is right. When he terminated me the first thing out of his mouth is that he was correct. So he is just looking for yes men to tell him what he wants to hear. So if they speak with him then maybe he gives a bad review.