The database is arranged in the same hierarchy as that used by Electronic Outlook Corporation (EOC).  The value of a Level-2 equipment category is equal to the sum of the Level-3 categories shown below.  A category's level can be determined by the number of non-zero digits.  For example ENTERTAINMENT ELECTRONICS (531000) is a Level-3 category.

5-3-0-0-0-0 CONSUMER & AUTOMOTIVE ELECTRONICS

5-3-1-0-0-0 ENTERTAINMENT ELECTRONICS

5-3-2-0-0-0 HOME ELECTRONICS

5-3-3-0-0-0 PERSONAL ELECTRONICS

5-3-5-0-0-0 AUTO ELECTRONICS