From Elektra Initiative

When using Elektra to store your application's configuration and state, please keep in mind the following rules:

• You are not allowed to create keys right under system or user.
• You are not allowed to create folder keys right under system or user. They are reserved for very essential OS subsystems.
• The keys for your application, called say MyApp, should be created under system/sw/MyApp and/or user/sw/MyApp.

Unused/Old Keys Left in the Database

Old/uninstalled software may leave unused keys into the Elektra database. Actually, this can also happen with regular text configuration files. Garbage collection of keys and files is done by the package manager or the sysadmin. The Elektra API and the kdb command line tool provide ways to find keys that were not accessed for a long time.

When a user is removed from the system, his keys disapear when his $HOME dir is removed.