Use of Jane Doe in a civil judgment doc?

Just wondering if anyone can tell me why Jane Doe would be used in a civil judgment, wherein the plaintiff (Farmers Insurance) is stating the matter's been resolved.

I've been seeing someone who says he has never been married and...lo and behold, I found a civil judgment on (his complete name ) and Jane Doe (his last name), husband and wife. Wow, what a shocker. Can anyone confirm to me that this means he really was married at the time of this judgment? I've done some research on this and it would seem so. Only other reason I could think of might be that he only told Farmers he was married for the lower premium, hence the Jane Doe reference? Of course, I'm just really in denial so I am probably reaching for straws here.

I don't want to confront him unless I know what I'm talking about.

Thanks.