Passport stamps (5)
I believe the answer is:
visas
'passport stamps' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for visas that I've seen before include "More than one travel document" , "travel permits" , "They allow the bearer to enter a country" , "They allow bearers to enter a country" , "Travel documents required by some countries" .)