Buried in a set of somewhat confusing announcements last week, Microsoft revealed that it is changing how it supports traditional versions of Office moving forward. Is this the end of Microsoft Office as we know it?

As a recap, Microsoft announced last week that it is aligning the development schedules for Windows 10 and Office 365. Given my focus on Windows, I pretty much just covered that aspect of the story: Windows 10 will now be updated with new features twice a year.

The Office 365 part of the announcement didn’t seem too interesting to me at the time. And once you really read through what they’re saying there, it’s still not all that interesting. After all, Office 365 customers pay a monthly or annual subscription fee and are kept up-to-date automatically, with fixes and new features. The schedule sort of doesn’t matter. If you stop paying, you lose access to the functionality.

But Microsoft also discusses something it calls “Office perpetual” in a separate but related post to its Office Blogs. And that bit, as it turns out, is a big change from how things have worked to date.

To understand why that is so, we need to decipher Microsoft’s terminology.

As you probably know, Microsoft offers various Office 365 subscription plans to businesses and consumers. Most of these plans include access to cloud-based services as well as locally-installable Office applications. On Windows, the most recent version of that locally-installable software is called Office 2016.

Microsoft really wants its customers to all move to subscription-based Office 365 offerings. But we are in a transitional period during which it offers access to its traditional, locally installable software in two ways: In standalone form (where you buy some version of Office 2016 or an individual application, like Word 2016) and as a subscription service.

Those standalone versions of Office are what Microsoft calls “Office perpetual.” They are limited in that they can only be installed on a single PC. But they are “perpetual” in that you pay once and can essentially use them forever … on only that one PC. The support lifecycle for these products is technically 10 years, with 5 years being what Microsoft calls “mainstream support,” during which new features can be added, and 5 years being “extended support,” during which Microsoft will only fix bugs. But there’s nothing stopping you from using a very old version of Office today. It’s not supported, perhaps, but it will still work.

On the subscription side, Microsoft offers an Office 365 solution called Office 365 ProPlus that is basically Office 2016 as a service. That is, it doesn’t provide access to cloud services and traditional Office applications. It just provides those traditional Office applications, which today is Office 2016.

Since the advent of Office 365, the fear in some quarters is that Microsoft will someday simply drop what it calls Office perpetual. In other words, if you want the Office desktop applications on Windows (or a Mac), you would need to subscribe to some Office 365 plan, be it Office 365 ProPlus, Office 365 Home, Office 365 Business Premium, or whatever.

Last week’s announcement does not state that Microsoft is moving in that direction. Instead, it spells out exactly how it will support Office 365 ProPlus and Office perpetual going forward. So in many ways, it is both changing the contract after the fact and supplying its customers with some clarity around how things will work going forward.

That said, the only major impact here, frankly, is to those people who wish to use “Office perpetual”. That is, if you would rather “own” Office 2016 (or some past or future version of the Office desktop applications) than pay monthly or annually for a subscription, then things are going to change.

“Starting October 13, 2020, Office perpetual in mainstream support will be required to connect to Office 365 services,” the Microsoft announcement notes. “For customers who aren’t ready to move to the cloud by 2020, we will also support connections from Office perpetual in mainstream support.”

I removed any references to Office 365 ProPlus from that quote to make it less cryptic. But it’s still confusing, I know. So let me translate it into plain English.

You can use any “Office perpetual” products with Office 365 services for the first five years of its product life cycle (during what Microsoft calls mainstream support). So you will be able to use Office 2016, the current version of “Office perpetual,” to connect to Office 365 services like OneDrive until October 13, 2020. After that date, you will need to purchase a newer version of “Office perpetual” (Office 2020 or whatever they call it) to continue using Office 365 services.

This doesn’t mean that Office 2016 (or any other “Office perpetual” version) will stop working. You can continue using these applications with local files in perpetuity—thus the name—and Microsoft will explicitly support the product with software fixes for the full tens years of support. So support for Office 2016 will end in October 2025, as you’d expect. But it will still “work.” There’s no cloud-based kill switch or whatever.

If you do not use Office 365 services, you have nothing to fear. (Well, other than data loss, I guess.) Perhaps you use Dropbox instead. Or whatever.

As Mary Jo Foley notes, the real point here is to push customers to Office 365. I feel like Microsoft is using some fear tactics here, frankly. But there are practical reasons to choose Office 365 over “Office perpetual,” including the fact that most Office 365 subscriptions let you use Office 2016 on multiple PCs, and switch between them at will.

“Microsoft also is letting its Office customer base know that as of October 13, 2020, Office 365 ProPlus will be the only fully featured, most up-to-date client that will connect to Office 365 services,” Foley explains. “Anyone using perpetual Office apps and clients may not get all the features at the time they are available to Office 365 ProPlus users. This change reflects what’s been happening with many other Microsoft products; the on-premises/local versions are updated less frequently and may not include all of the functionality that is in the cloud versions.”

Confusing? Sure. But it does look like Microsoft will keep traditional Office around for the foreseeable future, which should please the Luddites out there. But don’t be surprised to see the firm address this when Office 2020, or whatever it’s called, is announced. Something tells me that the days of “Office perpetual” are not really all that perpetual.