How can I install a new keyboard layout in KDE 4?

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http://unix.stackexchange.com – I have a custom X11 keyboard layout that I can use with setxkbmap. But after some searching I've found that apparently just having the XKB layout file isn't enough to set it as a new keyboard layout in KDE 4. What I would like to have my custom layout be recognized by the KDE system so that I can choose it using the systray applet, or install it as the default using the System Settings module. What do I need to do to make this happen? If it's complicated, that's fine, I would still like to know what is involved. I've looked at this question which seemed to be related, but it apparently is abo (HowTos)