https://faq.i3wm.org/questions/Frequently asked questions and answers about the i3 window managerenCopyright i3, 2012Wed, 11 Jun 2014 08:14:35 +0000https://faq.i3wm.org/question/3949/match-windows-without-class/Is it possible to use a *WM_CLASS* test to match windows without a class? The reason I ask is the following match only matches windows that have a *WM_CLASS* set, the others are ignored: assign [class="^(?!Steam)" title="(StarConflict.*|Trine|Spiral.*|Iesabel|The Witcher.*|Teslagrad.*|Dust:.*|Bastion|Painkiller.*|RaceTheSun|Rochard)"] $ws9 This matches, for instance, The Witcher 2 Launcher which has a `WM_CLASS` property: [xprop output](http://pastebin.com/BgdBHtGb) but not, for instance, Teslagrad, which does not: [xprop output](http://pastebin.com/7bUPYUxG) Wed, 11 Jun 2014 01:36:26 +0000https://faq.i3wm.org/question/3949/match-windows-without-class/https://faq.i3wm.org/question/3949/match-windows-without-class/?comment=3952#comment-3952I don't have anything to test with, but maybe `[class="^$"]` matches (it matches empty strings, I'm not sure how missing properties are mapped). Wed, 11 Jun 2014 08:14:35 +0000https://faq.i3wm.org/question/3949/match-windows-without-class/?comment=3952#comment-3952