Orders stamps with head scrubbed out (5)
I believe the answer is:
ranks
'orders' is the definition.
('rank' can be a synonym of 'order')
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ranks that I've seen before include "Lines or rows of people or things" , "Grades, in armed forces say" , "Classifies" , "Series of soldiers" , "Positions of seniority" .)