Documentation for Red Hat Enterprise Linux 3 (section 18.104.22.168) mentions these files in
The documentation for RHEL 5 also mentions them.
Documentation for RHEL 6 does not mention any files except for
If these files are mentioned in Ubuntu documentation, I can't find it. I also searched some of the Red Hat 5.x Release Notes, and I can't find it in there either.
The patch (against 2.4.11) to support these files (except
sysrq-timer) was submitted to the kernel mailing list by Crutcher Dunnavant back in 2001; I don't know if it was ever officially accepted.
Checking current systems, I can't find the files (except for the
sysrq file) on a RHEL 5.6 system nor on an Ubuntu Server Lucid Lynx 10.04.
What is the status of these files? Are they Red Hat-specific? Are they part of the kernel? Was the support removed? When?