the Rules of signing assemblies

In advanced settings models there is a check mark Подписывать сборки. After installation when you generate will be optionally generated files with the file extension .snk (if the project was generated previously, it will also be overwritten file AssemblyInfo.cs).

To sign the assemblies from Flexberry Designer necessary utility sn.exe, which you should copy to a folder Flexberry Designer (this utility can be found in subfolders of the folder C:\Program Files\Microsoft SDKs\Windows (this folder in the system may not be), it is better to be taken from the subfolder with the name “7.0”).

About signing assemblies, you can also read the msdn.