http://www.dragthing.com/blog/?p=285

Here at TLA Systems, we take our responsibility to protect innocent minds very seriously.

Have you, or somebody close to you, ever turned your calculator upside down and accidentally seen a mildly suggestive word? Have you ever been in a maths class, and had to put up with groups of giggling boys performing elaborate calculations that are not part of the lesson?

Yes, it’s one of the main problems affecting the calculator industry today, the so-called “calculator words”. These otherwise harmless devices can be made to display smut at the press of a few buttons. Added to that, the iPhone App Store is very strict about having inappropriate content in apps. Nobody wants their app to get a 17+ rating, or worse, to be rejected entirely.

Which is why we are happy to announce that the latest version of our PCalc scientific calculator for the iPhone contains a new patent-worthy profanity filter.

Simply enter a number such as “5318008″, turn the calculator upside down, and the offending word will be discreetly censored. Many common calculator words have been included as standard, and we plan to increase this over time via software updates.