Make the asdf keys type brackets in AltGr mode. - On German keyboards, typing the brackets and braces like {[]} is quite annyoing (especialy when programming) so I remapped them to AltGr+asdf which is much better imo. This is tested on Fedora Linux but it should work on most Linuxes.

asdfbrackets

# Save this file as /usr/share/X11/xkb/symbols/asdfbrackets

# Thanks to: BRPocock's answer at 
# https://ask.fedoraproject.org/en/question/73014/how-to-assign-ctrl-up-to-home-ctrl-down-to-end-ctrl-left-to-page-up-and-ctrl-right-to-page-down/?answer=73021#post-id-73021

partial alphanumeric_keys
xkb_symbols "asdfbrackets" {
    name[Group1]="brackets on AltGr+asdf";

    key <AC01>	{ [         a,          A,    braceleft,          AE ] };
    key <AC02>  { [         s,          S,  bracketleft,       U1E9E ] };
    key <AC03>	{ [         d,          D, bracketright,         ETH ] };
    key <AC04>	{ [         f,          F,   braceright, ordfeminine ] };
};

# Usage: 
# Run as user: 
# setxkbmap -v
# Append +asdfbrackets to symbols, for example:
# setxkbmap -v -symbols 'pc+de+us:2+inet(evdev)+asdfbrackets'

# For simplicity and because I am starting bash by default, I just added this to my .bashrc:
# setxkbmap -v -symbols 'pc+de+us:2+inet(evdev)+asdfbrackets' > /dev/null
# However, there is a better solution given in the linke above.

For some reason, upgrading to F43 cleared that file :(

Recreate it with the contents from two posts above, path: sudo vim /usr/share/X11/xkb/symbols/custom

It was not deleted, I just didn't see it in the xkb.rpmmoved directory. Should be a one time issue, but placing the file in a user directory might be beneficial in general.

Details: https://bugzilla.redhat.com/show_bug.cgi?id=2407061