To match any of the available end-user device environment variables, use the Wildcard or Regular Expression
You may enter any environment variable that the devices may have, but the prompted list in the dialog box will show the last connected device’s environment, or the Eclipse internal browser’s.
In case there is no such device available, the dialog box will show the information on how to connect a device:
Example expression:
{ Dev: "cap-touch" }
The Language code matching expression is used to select language from the end-user device. Language codes can be matched using simple languages (without country or other additions such a language variant, e.g. “en” for any English language).
The language code selector expression is typically used when you require a certain UI for a region, e.g. you could create a selector that matches the languages available in the European Union because your application has legal information to display, and another for the Unites States.

All languages will be shown when unselecting the Simple checkbox.
Example expression:
{ Lang: "fr" }
The Device match expression is used to match a feature from the end-user device. It is divided into the feature groups Capabilities, Orientation, UI Theme, Size, Type and Operating System. This selector expression is used to provide a UI design that matches the device, e.g. you do not wish to display a panel that wants to record a video when the device doesn’t have this capability, you have a very dark panel that would suit the Android theme, or that you have two versions of a specialized panel depending of the device orientation.
The dialog box below shows all the current matches available:
Example expression:
{ Dev: "dev-isDesktop" }