Declare that this application requires access to restricted accounts of a certain type. The default value is null and restricted accounts won\'t be visible to this application. The type should correspond to the account authenticator type, such as "com.google".

Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

[Android Documentation]