Castor-integration.md

@@ -12,7 +12,7 @@ The first two aspects ensure that assessors create and find proper Castor record
 
 # Import
 
-PEP can import (several types of) data from the Castor system. The import stores the data into PEP columns, from where they can be retrieved by PEP users.
+PEP can import (several types of) data from the Castor system. The import stores the data into PEP, from where they can be retrieved by PEP users. PEP ensures that Castor data are imported into the proper row by storing participants' Castor record IDs in a short pseudonym column.
 
 ## Data types