All Symbian applications must be signed before they can be installed. All applications which use capability-protected APIs, where the capability cannot be granted by the end user, have to be certified. Such certification can be obtained through Symbian Signed.
Signing is a means of encoding a digital certificate into the application installation file. The certificate identifies the application’s vendor, and grants access to capabilities defined during the build process.
The signing process is described in detail on the Symbian Signed website.
If your application only needs user capabilities (LocalServices, NetworkServices, ReadUserData, WriteUserData, UserEnvironment, andLocation), you can self-sign the application.
When the end users are installing a self-signed application, they are informed that the application is untrusted and may decide to abort the installation. In Nokia E-series devices the user must change a setting to allow self-signed applications to install.
Sign the sis installation file with any private key. You can use the MakeKeys application to create the needed private key and, for example, SignSIS to sign the application. Both applications are delivered with the SDK. For more information, see How to sign a .Sis file with Self-Sign Certificate in the Forum Nokia Developer Community Wiki.
The other signing options (Open Signed, Express Signed and Certified Signed) are described in detail in The Complete Guide to Symbian Signed.
The UID value you need to use for your application depends on whether your application is signed or self-signed. For more information, see UID and How to use UIDs.