This week, Microsoft claimed that it would add “full portrait support” to Windows 8.1. If you’re familiar with Windows 8, which already does support portrait mode, you may find this confusing. Here’s what’s changing.

“Coming with Windows 8.1, building on our support for small tablets, we're really committed to completing the scenario, including full portrait support,” Microsoft corporate vice president  Antoine Lebond said during a speech at Computex this week. “These devices obviously want to be held in portrait mode. They're much more comfortable to hold that way.”

(Thanks to Mary Jo Foley for tipping me off to this information.)

According to LeBlond, “full” portrait mode support includes the following changes:

Better Start screen layout. In Windows 8/RT today, you can rotate a device and the Start screen will rotate to match. But few would claim that the Start screen works well in this way, and rather than support a Windows Phone-type layout, it simply continues scrolling horizontally. Leblond says that Windows 8.1 will include “Start screen layouts that work much better,” though he declined to expand on what that meant exactly.

In-box app support for portrait mode. “All of the apps that are ‘in the box’ [i.e. ship with Windows 8] actually work just as well in portrait mode as they work in landscape,” Leblond said.

Support for smaller, thinner devices. “We did some work at the device interface level around edge detection and things like that to make it easier to have smaller bezels on these devices so that [hardware makers] could build exactly the kinds of devices they want, and Windows 8.1 will be great on them,” Leblond noted.

I’m curious to see these changes in action, but as anyone who’s used an Amazon Kindle Fire HD, Google Nexus 7, Apple iPad mini or similar device can tell you, mini-tablets do indeed shine and feel more natural in portrait mode. Fully supporting this is not just smart, it’s crucial.