# Feature Archives

The feature packaging information is placed into a separate Java .jar. Standard Java jar facilities are used for constructing feature archives. Feature archives reference separately packaged plug-in archives (see next section) and non-plug-in files.

Features are identified using a structured identifier based on the provider internet domain name. For example, organization eclipse.org produces feature org.eclipse.jdt. The character set used for feature identifiers is as specified for plug-in identifiers (see Plug-in Manifest).

The recommended convention for naming the feature archives is
`<id>_<version>.jar`

Where `<id>` is the feature identifier and `<version>` is the full version identifier contained in the respective feature.xml. Note that this is a recommended convention that minimizes chance of collisions, but is not required by the Eclipse architecture. For example, the following are valid feature archive names

`org.eclipse.jdt_2.0.0.jar`
`org.eclipse.pde_2.0.jar`
`my_feature.jar`

Internally, each feature archive is packaged relative to its feature directory (but not including the directory path element). The archive has the following structure

`feature.xml`
`feature<_locale>.properties (see "Translated Feature Information")`
`other feature files and subdirectories (TBD)`
`META-INF/`
`Java jar manifest and security files`

Note that feature archives do not contain their constituent plug-ins and fragments.