In Access 2003-2000
If you open up Access and select Tools ... Options and then select the Tables / Queries tag you will find a field called
AutoIndex on Import/Create:
If you have any fields in your database with these prefixes or suffixes, you will find that you have indexes on the field whether you like it or not. You may as well clear the "Auto Index on Import/Create" text box on this tab as this is a very unnecessary feature.
The standard keys featured here are
So look out for those fields cause your database will be bigger and slower than you think.
In Access 2007
Follow these pictures to see how to change this "too tricky" behavior