Such characters a matter for the drug squad? (5,4)
I believe the answer is:
upper case
'such characters a matter' is the definition.
I can't judge whether this defines the answer.
'the drug squad?' is the wordplay.
'the drug' becomes 'upper' (a type of stimulating drug).
'squad?' becomes 'case' (I can't justify this - if you can you should give a lot more credence to this answer).
'upper'+'case'='UPPER-CASE'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for upper case that I've seen before include "Description of letters like THESE" , "LSD, but not pot, is in this" , "UNISON is in it!" , "Formal description of capital letters" , "(capitals here, please)" .)