Row about some rare items (4)
I believe the answer is:
tier
'row' is the definition.
(a tier is a row of things)
'about some rare items' is the wordplay.
'about' shows that the letters should be reversed in order.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'reit' is hidden in the letters of 'rare items'.
'reit' backwards is 'TIER'.
(Other definitions for tier that I've seen before include "'Level, grade (4)'" , "one doing Bond" , "Level within hierarchy" , "Person joining" , "band" .)