Translations:Dolphin/File Management/127/en
You can, for one, alter this in → → → → . This is the same as running kcmshell5 filetypes in a Konsole.
You can, for one, alter this in Kickoff → Computer → System Settings → Common Appearance and Behavior → File Associations. This is the same as running kcmshell5 filetypes in a Konsole.