It's quite likely that you missed an Apple (AAPL 0.52%) storyline at the end of June, or that you saw it and brushed it aside like I did, believing it to be inconsequential.

Last month, the U.S. Patent and Trademark Office published a patent application that the Mac maker has filed for, detailing a multi-function input port that could merge a USB port and SD card slot into one. Apple originally applied for the patent in December 2011, and it has yet to be awarded. One of the primary benefits of merging the two ports would be to facilitate even thinner designs.

Consumer preferences are quickly shifting to the thin-and-light laptop segment, an area that NPD says that the MacBook Air dominates with 56% market share. This patent application might not seem like a game-changer, but DIGITIMES believes that rival Ultrabook makers competing in the market for thin and light laptops are worried that the move would give Apple another leg up. With as thin as laptops have become, every millimeter counts; a combined input port could save 12 to 13 millimeters in external designs.

The possible move is similar to another seemingly minor detail that's arguably underappreciated: Apple's MagSafe power adaptors. The magnetic power cord was unveiled in 2006 as an added convenience, reducing the risk that people would trip on cords and laptops would crash into floors. Apple also patented the connector, which is why rivals still can't use it. Microsoft Surface uses a magnetic power cord, with the big difference being that Microsoft's version carries data along with power. Microsoft has applied for a patent of its own.

Alone, these are all minor details that most PC vendors have overlooked. Combined, they offer conveniences that give Apple an advantage. Rivals already have to watch out for Apple's MacBook Air design patent, which covers the overall wedge look. Even though Apple isn't immune to the PC market's broad weakness right now, it's still got some tricks up its sleeves.