Recognized desktop entry keys

Keys are either OPTIONAL or REQUIRED. If a key is OPTIONAL it may or may not be present in the file. However, if it isn't, the implementation of the standard should not blow up, it must provide some sane defaults.

Some keys only make sense in the context when another particular key is also present and set to a specific value. Those keys should not be used if the particular key is not present or not set to the specific value. For example, the Terminal key can only be used when the value of the Type key is Application.

If a REQUIRED key is only valid in the context of another key set to a specific value, then it has to be present only if the other key is set to the specific value. For example, the URL key has to be present when and only when when the value of the Type key is Link.

Some example keys: Name[C], Comment[it].

Table 2. Standard Keys

KeyDescriptionValue TypeREQ?Type
Type This specification defines 3 types of desktop entries: Application (type 1), Link (type 2) and Directory (type 3). To allow the addition of new types in the future, implementations should ignore desktop entries with an unknown type. stringYES 
Version Version of the Desktop Entry Specification that the desktop entry conforms with. Entries that confirm with this version of the specification should use 1.0. Note that the version field is not required to be present. stringNO1-3
Name Specific name of the application, for example "Mozilla". localestringYES1-3
GenericName Generic name of the application, for example "Web Browser". localestringNO1-3
NoDisplay NoDisplay means "this application exists, but don't display it in the menus". This can be useful to e.g. associate this application with MIME types, so that it gets launched from a file manager (or other apps), without having a menu entry for it (there are tons of good reasons for this, including e.g. the netscape -remote, or kfmclient openURL kind of stuff). booleanNO1-3
Comment Tooltip for the entry, for example "View sites on the Internet". The value should not be redundant with the values of Name and GenericName. localestringNO1-3
Icon Icon to display in file manager, menus, etc. If the name is an absolute path, the given file will be used. If the name is not an absolute path, the algorithm described in the Icon Theme Specification will be used to locate the icon. localestringNO1-3
Hidden Hidden should have been called Deleted. It means the user deleted (at his level) something that was present (at an upper level, e.g. in the system dirs). It's strictly equivalent to the .desktop file not existing at all, as far as that user is concerned. This can also be used to "uninstall" existing files (e.g. due to a renaming) - by letting make install install a file with Hidden=true in it. booleanNO1-3
OnlyShowIn, NotShowIn

A list of strings identifying the desktop environments that should display/not display a given desktop entry.

By default, a desktop file should be shown, unless an OnlyShowIn key is present, in which case, the default is for the file not to be shown.

If $XDG_CURRENT_DESKTOP is set then it contains a colon-separated list of strings. In order, each string is considered. If a matching entry is found in OnlyShowIn then the desktop file is shown. If an entry is found in NotShowIn then the desktop file is not shown. If none of the strings match then the default action is taken (as above).

The same desktop name may not appear in both OnlyShowIn and NotShowIn of a group.

string(s)NO1-3
DBusActivatable A boolean value specifying if D-Bus activation is supported for this application. If this key is missing, the default value is false. If the value is true then implementations should ignore the Exec key and send a D-Bus message to launch the application. See D-Bus Activation for more information on how this works. Applications should still include Exec= lines in their desktop files for compatibility with implementations that do not understand the DBusActivatable key. booleanNO 
TryExec Path to an executable file on disk used to determine if the program is actually installed. If the path is not an absolute path, the file is looked up in the $PATH environment variable. If the file is not present or if it is not executable, the entry may be ignored (not be used in menus, for example). stringNO1
Exec Program to execute, possibly with arguments. See the Exec key for details on how this key works. The Exec key is required if DBusActivatable is not set to true. Even if DBusActivatable is true, Exec should be specified for compatibility with implementations that do not understand DBusActivatable. stringNO1
Path If entry is of type Application, the working directory to run the program in. stringNO1
Terminal Whether the program runs in a terminal window. booleanNO1
Actions Identifiers for application actions. This can be used to tell the application to make a specific action, different from the default behavior. The Application actions section describes how actions work. string(s)NO1
MimeType The MIME type(s) supported by this application. string(s)NO1
Categories Categories in which the entry should be shown in a menu (for possible values see the Desktop Menu Specification). string(s)NO1
Implements A list of interfaces that this application implements. By default, a desktop file implements no interfaces. See Interfaces for more information on how this works. string(s)NO 
Keywords A list of strings which may be used in addition to other metadata to describe this entry. This can be useful e.g. to facilitate searching through entries. The values are not meant for display, and should not be redundant with the values of Name or GenericName. localestring(s)NO1
StartupNotify If true, it is KNOWN that the application will send a "remove" message when started with the DESKTOP_STARTUP_ID environment variable set. If false, it is KNOWN that the application does not work with startup notification at all (does not shown any window, breaks even when using StartupWMClass, etc.). If absent, a reasonable handling is up to implementations (assuming false, using StartupWMClass, etc.). (See the Startup Notification Protocol Specification for more details). booleanNO1
StartupWMClass If specified, it is known that the application will map at least one window with the given string as its WM class or WM name hint (see the Startup Notification Protocol Specification for more details). stringNO1
URL If entry is Link type, the URL to access. stringYES2