Dvorak Simplified Keyboard closed out. Apple also includes a Dvorak variant they call "Dvorak – Qwerty ⌘". With this layout, the keyboard temporarily becomes QWERTY when the Command (⌘/Apple) key is held down. By keeping familiar keyboard shortcuts like "close" or "copy" on the same keys as ordinary QWERTY, this lets some people use their well-practiced muscle memory and may make the transition easier. Mac OS and subsequently Mac OS X allow additional "on-the-fly" switching between layouts: a menu-bar icon (by default, a national flag that matches the current language, a 'DV' represents Dvorak and a 'DQ' represents Dvorak – Qwerty ⌘) brings
Dvorak Simplified Keyboard change. The Dvorak layout is often used in economics textbooks as a standard example of network effects, though this method has been criticized. Most keyboards are based on QWERTY patterns, despite the availability of other keyboard patterns, including the Dvorak. Although DSK is implemented in many languages other than English, there are still potential issues. Every Dvorak implementation for other languages has the same difficulties as for Roman characters. However, other (occidental) language orthographies can have other typing needs for optimization (many are very different from English). Because Dvorak Simplified Keyboard was optimized for the statistical distribution of letters of