Concerning the content of certain records (2,2)
I believe the answer is:
in re
'concerning' is the definition.
(thesaurus)
'the content of certain records' is the wordplay.
'the content of' indicates a hidden word.
'IN RE' can be found hidden inside 'certain records'.
(Other definitions for in re that I've seen before include "With regard to" , "Concerning (L)" , "In the matter of (Lat.)" .)