Account Groups

Typically accounts are arranged in a tree. Typically, Accounts that are not leaf accounts have a number that ends in zero. For example:
        300             Expenses
         |
         +--310         Living Expenses
         |   |
         |   +--311     Beer
         |   |
         |   +--312     Cable
         |
         +--320         Business Expenses
         |   |
         |   +--321     8-inch Floppies
         |   |
         :   :