I found this information in the Peachtree help:
Typos and data corruption: Sometimes you will enter a misspelling in an address field. Since all entries are saved to AFLOCAT.DAT, this misspelling will stay in the file. Say you've typed both Centerville and Cneterville in a City field; both entries have been saved in AFLOCAT.DAT. However, Centerville is of course the correct spelling, and it is used in customer records stored in Peachtree while Cneterville is not. If you want to get rid of this misspelled entry, you need to run data verification to restore AFLOCAT.DAT to its previous state. Running data verification will never delete entries used in records stored in the Peachtree database.