Translation of "funktionstast" into English

An item on mobile devices (e.g. mobile phones) that consists of a key plus a software label describing the current function of the key.

Any of the 10 or more keys labeled F1, F2, F3, and so on, that are placed along the left side or across the top of a keyboard (or both) and are used for special tasks by different programs. The meaning of a function key is defined by a program or, in some instances, by the user. Function keys are used in application programs or the operating system to provide either a shortcut for a series of common instructions (such as calling up a program's on-screen help facility) or a feature that is not otherwise available.

One of the two unlabeled keys located just below the display area on a mobile phone. These keys are called "soft" because their functions change to fit the context. Labels in the lower part of the mobile screen tell users what the soft keys do.