Dear Rich: I have an idea for an iPhone App that is a beginner's guide to an art craft. In this guide I want to write about different products that have different applications in this craft (such as types of paint for a watercolor artist). Does selling an artist material guide for the IPHONE infringe on trademarks of different products just by mentioning the name? Short Answer Dept. You're fine as long as you don't imply endorsement from any of the companies mentioned in your App. Wow, that was easy! Since we've answered your question so quickly and have all this space left, we wanted to let readers know that we're in the middle of a couple of exciting things. First, we've rediscovered tapioca pudding, and second we recently saw a feel good movie that, although it didn't make us feel that good, was kind of interesting from a legal POV.