The interesting yet ditched by Microsofts “Sets” or “Windows Sets” feature may make a comeback in new Preview builds. Enthusiasts have been able to dig into the code for Windows SDK Build 19577 and notice the presence of Sets code.

“Sets” or “Windows Sets” enable adding the two kinds of tabs, Web tabs and also Apps tabs, once you launch an app. Web tabs are a browser or Microsoft Edge tabs related to the app’s tasks, while Apps tabs are more windows of the app that you are using. Microsoft notes that

With Sets, what belongs together stays together — making it easier and faster to create and be productive. The concept behind this experience is to make sure that everything related to your task: relevant webpages, research documents, necessary files and applications, is connected and available to you in one click. As Office, Windows and Edge become more integrated to create a seamless experience, so you can get back to what’s important and be productive, recapturing that moment, saving time — we believe that’s the true value of Sets.

You can watch Sets in action in the video below.