Apple is at least considering a system to allow customers to sell or lend their iTunes content.
The patent applies to content such as ebooks, music, movies and apps, and covers cloud-based content as well. Amazon recently won a patent for a very similar system, although it restricts sales to third parties.
The idea is one which, clearly, wouldn't play well with content owners. But Apple's aiming to win them over by giving them a great deal of control over the circumstances in which content can be transferred. It provides for them to get a cut of the proceeds, for a start.
And it also allows the original creator or publisher to impose conditions - that the item might not be resold for a certain period, for example, or must have a minimum price.
There could be limits on the number of times an item could be transferred, or even to whom - the patent suggests that resale or loans could be restricted to members of a user's social network, for example.
The move would go some way to answer the concerns of those users who resent having a license to a book, for example, rather than the book itself. The principle's currently under legal challenge, with start-up ReDigi - a marketplace for second-hand digital content - battling EMI over whther digital music can legally be resold.