AAAAAH. Today I discovered a very nice implementation of business rules done by HP. At home I have a HP photosmart 8250 printer who today displayed the message:"the ink cartridges are past its expiration date!"
So each ink cartridge has a date and the code in the printer is testing this business rule to force me to buy new cartridges.... It is not enough to get printer drinking cartridge ink like we drink water under 100F, but in case we are not printing enough, this rule enforces business.
Sad commercial behavior, bad rule, I'm just now hoping they are using a rule engine so I can change the rule on a fly... A dream.