The european keyboard layout is based on the us keyboard layout, but with the possibility to also type nearly all characters from nearly all european languages, wich diverge from the us keyboard layout.

You can check out the layout here:
https://eurkey.steffen.bruentjen.eu/layout.html
Click on the tabs to see what inputs are possible (needs javascript enabled).

Note:
The developers of EurKEY wrote, that their program is included in xkeyboard-config 2.12 and newer.
You can find that note here:
https://eurkey.steffen.bruentjen.eu/download.html#tab1
As far as I understand that is the source and the binary package for apt is: xkb-data.
On both computers where I tested the following configuration that package is installed.

# Setting up the eu keyboard layout under Devuan 5.0.1

## Set it up for the Xserver only
Simply run:
setxkbmap eu

## Set it up for the tty

1.
In
/etc/default/keyboard
set
XKBLAYOUT="eu"

2.
Check locales with
locale

2a.
If it does not show
en_US.UTF-8
change that by running
dpkg-reconfigure locales
and choose
en_US.UTF-8

3.
After that run
dpkg-reconfigure keyboard-configuration
and choose
Generic 105-key PC

3a.
In the next screen it will ask:
"Keep current keyboard layout in the configuration file?"
choose
Yes

3b.
In the third screen it will ask for
Key to function as AltGr:
choose
Right Alt (AltGr)

3c.
And in the last screen it will ask for
Compose key
choose
No compose key

4.
Then reboot.

Please report it here if that guide does not work for you or when you could get it to work with a different method. :)

# 1. Browse the stuff for your device
Go to:
=> https://support.brother.com/g/b/product … content=dl
and search for your device.

Select:
> Linux
as OS

Select:
> Linux (deb)

If it is complaining about that the software is not available in your language, just choose another language.

# 2. Aggree to the EULA while crossing your fingers behind your back.

# 3. Download all the stuff you need and install it.
The website will print you some information about installation and usage, but it can be that this is incomplete (as it was in my case) or outdated (as it was in my case too).
The last Debian version in their support FAQ is Debian 6! So...

## Additional steps I needed to do after install all of the stuff (printing and scanning) was the following:

### 4. Adding user to needed usergroups
The usergroup for printing is lpadmin.
The usergroup for scanning is scanner.
> adduser USERNAME lpadmin
> adduser USERNAME scanner

### 5. Install additional package(s) from the repo.
> apt install libusb-0.1-4

### 6. Add the device to udev rules
Open the file:
> /lib/udev/rules.d/60-libsane1.rules
and adding at the bottom of this file the lines:
Note:
> # Brother scanner
> FOLLOWED BY THE LINE SPECIFIC FOR YOUR DEVICE (LOOK AT BROTHER SUPPORT FAQ)

### 7. Copy specific files from /usr/lib64/ to /usr/lib/

Example for brscan3:

> cp /usr/lib64/libbrscandec3.so /usr/lib
> cp /usr/lib64/libbrscandec3.so.1 /usr/lib
> cp /usr/lib64/libbrscandec3.so.1.0.0 /usr/lib

> cp /usr/lib64/sane/libsane-brother3.so /usr/lib/sane
> cp /usr/lib64/sane/libsane-brother3.so.1 /usr/lib/sane
> cp /usr/lib64/sane/libsane-brother3.so.1.0.7 /usr/lib/sane

### 8. Reboot the computer
> reboot

If you have any questions or improvements for this short help text please post them.

# Hack bonus
## Printing greyscaled with empty colour cartridges.
One of the advantages of Brother devices over other vendors is imho, that many (or all?) of their printers are checking the filling level of the cartridges with an optical sensor (light, laser, what ever).
For this the beam is directed to a small window on the cartridge, if it goes throught, that will be registered as "cartridge is empty" and the printer wont print, no matter if the other three cartridges are full or not.
The user can just put a non-transparent sticky tape over both sides of that window and the printer will register the empty cartridge as full.
WARNING this has the potential to damage the printer, because it draws air into the system instead of ink. But this is only what the vendors say, maybe it is not true.
If you really know if it is true or not please post it here!