The "layout-devices" element is the root element of this schema. It must contain zero or more "device" elements that each define the configurations available for a given device. These definitions are used in the Graphical Layout Editor in the Android Development Tools (ADT) plugin for Eclipse. A device element must contain at most one "default" element followed by one or more "config" elements. The "default" element defines all the default parameters inherited by the following "config" elements. Each "config" element can override the default values, if any. A "device" element also has a required "name" attribute that represents the user-interface name of this device. The parametersType define all the parameters that can happen either in a "default" element or in a named "config" element. Each parameter element can appear once at most. Parameters here are the same as those used to specify alternate Android resources, as documented by http://d.android.com/guide/topics/resources/resources-i18n.html#AlternateResources Specifies the configuration is for a particular Mobile Country Code. Specifies the configuration is for a particular Mobile Network Code. Specifies that the configuration is for a particular class of screen. Specifies that the configuration is for a taller/wider than traditional screen. This is based purely on the aspect ration of the screen: QVGA, HVGA, and VGA are notlong; WQVGA, WVGA, FWVGA are long. Note that long may mean either wide or tall, depending on the current orientation. Specifies that the configuration is for a screen that is tall (port) or wide (land). Specifies the screen density the configuration is defined for. The medium density of traditional HVGA screens (mdpi) is defined to be approximately 160dpi; low density (ldpi) is 120, and high density (hdpi) is 240. There is thus a 4:3 scaling factor between each density, so a 9x9 bitmap in ldpi would be 12x12 is mdpi and 16x16 in hdpi. The special nodpi density that can be used in resource qualifiers is not a valid keyword here. Specifies the touch type the configuration is defined for. If your configuration uses a soft keyboard, use the keyssoft value. If it doesn't and has a real keyboard, use keysexposed or keyshidden. Specifies the primary text input method the configuration is designed for. Specifies whether the primary non-touchscreen navigation control is exposed or hidden. Specifies the primary non-touchscreen navigation method the configuration is designed for. Specifies the device screen resolution, in pixels. Specifies the actual density in X of the device screen. Specifies the actual density in Y of the device screen. The configType defines the content of a "config" element in a "device" element. A "config" element can have all the parameters elements defined by "parameterType". It also has a required "name" attribute that indicates the user-interface name for this configuration.