When we say signature, we generally mean the user's personal signature:
Strictly speaking, this 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, you provided the IMEI code of your tester, and Symbian issued you a "development certificate". You use this certificate to sign your Test Software. You are responsible for your "development behavior"! That's all. In addition, the development certificate is valid for half a year from the date of issuance, but within the validity period of the certificate, there is no limit on the use time after the program is signed and installed.
Imei = international mobile equipment identity = international mobile equipment identity card. This is similar to your "resident ID card". This thing belongs to the privacy scope. Symbian will not directly input this information on the website to protect users' privacy.