Here are some general tips for using classes:
Set up classes on the basis of the type of reporting that you
want to do, and consider how you want to see your business
segmented on reports.
Set up a class such as "other" that you can use to
deliberately classify transactions that don't fit into any
specific class that you've defined.
Don't use classes for two different purposes.
For example, don't create classes for tracking office
locations in addition to tracking partners.
Consistently enter the class information on your forms and
registers to ensure that this information is valid and useful.