Creating Konqueror Service Menus (aka contextual menus)

Konqueror Service Menues are additonal options that are displayed when you right-click on a file in Konqueror. They are file-type specific, meaning you can define which options are displayed depending what type of file you are right-clicking. Mac-people call these "contextual menues". A good tutorial is https://techbase.kde.org/Development/Tutorials/Creating_Konqueror_Servic...
In short: In the directory /opt/kde3/share/apps/konqueror/servicemenus there is a buch of desktop files. Just duplicate one, rename it and edit its content to please you. In the following example I have created a new file (pdfpic.desktop), that adds a menu option that is displayed when I right-click jpg files and it starts an editor with which I can add or modify the embedded rdf (resource description framework) information of a jpeg file. The editor is a java application and the %U sais, that if many files are simultaneously right-clicked they should be opened in one instance of the program.
[Desktop Entry]
ServiceTypes=image/jpeg
Actions=openInRdfpic
[Desktop Action openInRdfpic]
Name=Edit metadata
Icon=background
Exec=/usr/lib/java2/jre/bin/java -jar /usr/local/rdfpic-2.1/rdfpic.jar %U