The patent, discovered by AppleInsider, reveals Apple’s plans to create a slim headphone plug. What this means is that by reducing the size of the plug, they can in turn reduce the size of the headphone port, ultimately reducing the size of the device in general. This slimmed down plug isn’t particularly revolutionary as for the most part, it will function like a regular plug.
However as you can tell in the diagram, one side has been shaven down thus allowing it to be thinner than before. Of course this could cause some issues with users as pretty much all headphone plugs these days are round, so by creating a D-shaped port, it will limit the number of headphones that can be used with the device.
A recent rumor has suggested that the iPhone 7 will be the thinnest iPhone yet and based on this patent, it would certainly seem to be headed in that direction. There is no guarantee that this is a feature Apple will bring to the table, but it does hint at Apple’s plans to try and slim their devices down as much as possible.