Typically, 'kill' is built into the shell, and you're undoubtedly invoking your shell's version of kill. So you need to send a bug report to your shell's maintainer, not to coreutils'.
For example, on my host: $ /home/eggert/opt/Linux-x86_64/coreutils-8.13/bin/kill -l | head -n 1 HUP $ kill -l | head -n 1 1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP So coreutils conforms, but the shell does not.
