Harry lets in police after a form of ID is produced (4,3)
I believe the answer is:
name tag
'form of id is produced' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'harry lets in police after a' is the wordplay.
I cannot quite see how this works, but
'police' could be 'met' (London Metropolitan Police) and 'met' is located in the answer.
'a' is found in the answer.
'harry' could be 'nag' (both can mean to consistently bother) and 'nag' is located in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for name tag that I've seen before include "One identifying" , "Identifying badge" , "Personal identification" , "Label proving ownership" , "Label to identify" .)