Symbian 是一個龜毛的平台，由於安全性的機制，每個程式都必須要簽章過 (可使用 Self-Sign Certificate，不需要正式憑證)，才能安裝在手機上。

一般的開發者如果要測試安裝程式，也必須申請測試用的簽章來簽署自己的程式。稍早的時候是一個稱為 Developer Certificate signing 的申請程序，但程序繁瑣，後來 SymbianSigned 提供了一個 OpenSign Program，開放給開發者申請只能用在特定幾個手機上的簽章。目前提供的簽章機制大致分為以下四種 (Source: Symbian Signed signing options)

• Open Signed, has updated and replaced Developer Certificate signing, making it easy for developers to sign applications for limited deployment to known devices, either for testing or for personal use. The online-only option is coming soon.
• Express Signed, a new option similar to Self Certification, is available to all developers, either directly (for those who own a Publisher ID), or via publisher partners (for those who do not).
• Certified Signed, has updated and replaced the mainstream signing option based on independent testing by a Symbian accredited Test House.
• TCTrustCenter, www.trustcenter.de/order/publisherid/dev, is the Certificate Authority for Symbian Signed, responsible for issuing and validating Publisher ID digital certificates (but existing ACS Publisher Certificates issued by VeriSign will remain valid for Open Signed and Certified Signed).

但是從年前到現在，SymbianSigned 的 OpenSign 因為太多人申請而掛掉了。一直到今天都還是停擺的狀態，真是惱人。