Strictly speaking, the user signature should belong to the "developer signature".

Because Symbian provides a kind of "development certificate" for software developers, the original intention is to let software developers do software testing.

This "development certificate" is associated with the IMEI code of the machine used for testing.

The software signed with this certificate can only be used on the machine corresponding to the IMEI code, not on other machines.

Our so-called "self-signature" is actually in this way.

To put it bluntly, you said you were developing software, and you provided the IMEI code of your tester.

Symbian gives you a "development certificate", and you use this certificate to sign your "test software".

You are responsible for your "development behavior"!

In addition, the development certificate is valid for three years from the date of issuance.

However, within the validity period of the certificate, there is no limit on the use time of the signed program.