Why do I have man pages of commands that don't exist?

view story

http://askubuntu.com – whatis panel-test-applets? I don't know. If I want to know I type: $ whatis panel-test-applets The answer is: panel-test-applets (1) - display installed applets I have the man page too, and I can read it: $ man panel-test-applets But there is no command. Maybe the command is not very useful, but is its man page useful? Does someone know how to install the command or what is its man page for? (HowTos)