Brick River category options can store optional abbreviations as well as names. For example, the system category States stores both a State Name and a two character abbreviation.
In View Base XML for Contacts Views, all State fields include the attribute, ExportAbbrev="true".
<Category Id="MailState" Name="State" FullName="Mailing State" CatType="States" ExportAbbrev="true" ColorCoded="false"/>
Whenever Contact Records are exported the two character abbreviation is included - because you need the state abbreviation to print on mailing labels, of course.