Details, if in charge, are particular (8)
I believe the answer is:
specific
'are particular' is the definition.
(similar in meaning)
'details if in charge' is the wordplay.
'details' becomes 'spec' (I can't justify this - if you can you should give a lot more credence to this answer).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'spec'+'if'+'ic'='SPECIFIC'
Can you help me to learn more?
(Other definitions for specific that I've seen before include "Explicit or in detail" , "Particular, distinct" , "Detailed" , "Definitive or exact" , "Particular, definite" .)