How to submit XKB layout variant to Xorg?

[matej.bjgar at atlas.cz]

I added a custom XKB layout variant to /usr/share/X11/xkb/rules/xorg.lst and /usr/share/X11/xkb/symbols/cz. I can set it using setxkbmap and it works. When I upgrade my distribution or update Xorg, the variant is gone. From what I've read, I concluded I can't reliably add a custom variant (or any layout modification) to XKB.

My variant is Colemak optimised for writing Czech letters. Some languages have its own Colemak variant in preinstalled layouts but not Czech and anyone typing with Colemak in Czech can use it.

What has to be done to have a variant added for distribution with Xorg?

The only answer I found is at https://lists.freedesktop.org/archives/xorg/2007-July/026537.html but the link in that letter leads to a site with text “Sorry, entering a bug into the product xkeyboard-config has been disabled.”

I'll be thankful for information relevant to this, especially for an answer to my question or some information about how to reliably add keyboard variant to XKB.
Matěj Bagar