LEADS name (mr, mrs, dr. etc) not mandatory how to?

[alter]

Hi, name prefix (Mr, mrs, dr. etc) is not mandatory. Mandatory is either firstname or lastname attribute, you don't have to enter title/prefix.

[yuri]

Should NOT have been posted in bug reports.

[elcopero]

I am trying to make leads "name" (mr, mrs, dr. etc) not mandatory but in Entity Manager its actually not mandatory. How to disable this?