My husband worked in HR in one of the public services, liaising with many more departments including County Councils, local Government, etc. These places are audited regularly to ensure that they have a diverse work force and certainly the need to tick a box to prove that means that there is positive discrimination happening regularly. It influences decisions where there might be two ethnically diverse people up for the same job who have similar qualifications, experience, etc, in that the box can be ticked. This can happen across the board for sex, disabilities, etc. However, I have heard many times where the minority person is picked even though they are not as qualified or experienced and that does cause resentment.
It is the same with most Universities. A young person who is from a Public School is expected to get much higher grades than someone from a State School. They are also expected to have a much higher profile even though the chances are they will be expected by their schools to fit in much more than someone from a State School. I understand all the reasons for it but I can't help thinking that if you are the person having to jump through the hoops, it can seem quite unfair.