Saving money by abbreviations

Case in point for the last post:
A large Swiss bank, lately in the news because of 2 billion bonuses for the management while needing state help to the tune of 20 billion, actually had a good example of how stupidity scales: There was an improvement drive to "abbreviate more and only write department names in the short form, thus about 10 bytes per email and 100 bytes per memo. At (I do not really know how many people work there) lets say 20.000 employees and a lots of memos and mails per day, this saves Gigabytes of NAS and SAN storage and frees up at least one FTE in the IT department".

Yay. Can you spot the mistake?