Police spotting (junction watch)

Even if you are carrying ID there is no need to give it to them unless they are arresting you or they have reasonable suspicion that you are up to no good.

Not quite.

They can require* your name and address for the purpose of a summons, or if they are arresting you / reporting you for an offence.

They may not require* your name an address if they have any suspicion of something, unless they are arresting you.

You do not have to provide any ID. If they don't believe the name and address that you give, they may arrest you for the purpose of ascertaining your name and address.

If you are driving, they may require your driving license, insurance docs etc...

PCSOs have some designated authority which provides them with the authority to require name and address (sometimes for the same reasons above), and refusal to comply is an arrestable offence.

• By "require", I mean you must give it to them, or they may arrest and charge you.