The sort of information they may require is:
what was the person doing;
what are they carrying;
why they are in an area;
and where they are going.
Because of the Stephen Lawrence Report, the officer must fill in a form saying why the person was stopped and give them a copy.
Not every time a police officer or police community support officer talks to a person will count as a stop. For example, if the officer is looking for witnesses, asks a person for general information about an incident, or is giving them directions - this does not count as a stop and the officer would not normally fill in a form.
But even in this case, if the person wanted, they could ask for a form and the officer must fill one out and give it to the person they have spoken to.
For more detailed information about citizens' rights regarding police stop and search, click here.