Cannot set keyboard layout with the locale, keyb and klayout boot options

[pkoroau]

This boot command line does not set the intended keyboard layout, instead the "us" keyboard layout is set:

linux (lo)/casper/vmlinuz boot=casper iso-scan/filename=/path/to/livedvd.iso nosplash locale=it keyb=it klayout=it

The same happens for the language codes it, fr, de, es, pt, ru.

# lsb_release -rd
Description: Ubuntu 13.10
Release: 13.10

# apt-cache policy casper
casper:
  Installed: 1.336ubuntu1
  Candidate: 1.336ubuntu1
  Version table:
 *** 1.336ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
        100 /var/lib/dpkg/status

[LAFFITTE Guy (tarski)]

The problem is still present in Xubuntu 22.04. It affects only the keyboard parameters.
It comes from the fact that certain parameters should ( from "man 7 casper" ) have aliases not recognized by the concerned program in file :
  /usr/share/initramfs-tools/scripts/casper-bottom/19keyboard
Keywords that are not recognized are :
  keyb, klayout, kvariant, kmodel