Apple says its App Store will begin to highlight recommended age ratings, moving them to a prominent display position near the application name. The move from the Information section to the main app page will make the rating one of the first things users see when they open the app description, Apple said. While Apple has not publicly commented on the change, some analysts suggest it was in response to concern from parents over the in-app content their children may be encountering, PC Magazine reported Thursday. In January, the photo-sharing service 500px was briefly removed from the App Store when it was found to contain images of nudity. The service was later re-instated with a 17+ rating. Apple\'s rating system has four categories; apps rated 4+ contain no objectionable material, while apps with mild or infrequent violence and mature content not suitable for young children receive a 9+ rating. More frequent offensive language, violence, or other themes like gambling put apps in the 12+ rating category, while the 17+ tag is reserved for apps often suggesting sexual content, nudity, alcohol, tobacco, and drugs.