FTP question

As a baseline, my knowledge of FTP and how it works is limited.
 
My question is based on the following scenario:
 
1> User1/Password1 initals an FTP request to the iSeries
2> Exit program on the iSeries recognizes User1/Password1 and changes it
to a "common" FTP "user profile" that has proper authority to put a file
3> FTP request to put a file to the iSeries is completed and the user
log's off
 
At a later date, how can I determine who User1/Password1 was... inorder to
properly process the data in the file.
 
TIA
Michael


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