A clerks duties include address corrections in which the shipper is charged a fee (used to be $5.00, not sure if that has changed since I retired). Re-wrap packages, re-label packages if the label has been ripped off or otherwise unreadable. Investigation sometimes is required to find the correct addressee. Overgoods are also part of the clerks duties. Customer counter is manned by full time clerks in my old local. If a driver cannot locate a particular customer, a clerk will call the addressee and get directions sometimes. Damaged packages are handled and cataloged by clerks also.
These are most of the duties of full time clerks. In my old local, if we caught a management person correcting a packages address, we would grieve it and always win.
If a driver happens to know the real address of a package and completes the correction or corrects it himself, he/she is taking money out of the bottom line of the company's money. There was once a process in the DIAD that would do this for the driver and get the money from the shipper that way. Not sure if that is still implemented or not.