I chose to remove that functionality from /etc/sysctl.conf , & instead use my custom file, now suitably renamed to be > 50, thus… /etc/sysctl.d/55-magic-sysrq.conf . Given this latter file is dedicated exclusively to this SysRq functionality, i preferred to use it to include explanatory documentation within it [all part of my habit of leaving breadcrumbs behind me].
Hence now:
gooeygirl@linux-Tower:~> **sudo sysctl --system**
[sudo] password for root:
* Applying /boot/sysctl.conf-4.12.9-1-default ...
kernel.hung_task_timeout_secs = 0
kernel.msgmax = 65536
kernel.msgmnb = 65536
kernel.shmmax = 0xffffffffffffffff
kernel.shmall = 0x0fffffffffffff00
vm.dirty_ratio = 20
* Applying /usr/lib/sysctl.d/50-coredump.conf ...
kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %e
*** Applying /usr/lib/sysctl.d/50-default.conf** ...
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.promote_secondaries = 1
net.ipv4.conf.all.promote_secondaries = 1
net.ipv6.conf.default.use_tempaddr = 1
fs.inotify.max_user_watches = 65536
**kernel.sysrq = 184**
dev.cdrom.autoclose = 0
fs.protected_hardlinks = 1
fs.protected_symlinks = 1
kernel.kptr_restrict = 1
*** Applying /etc/sysctl.d/55-magic-sysrq.conf ...**
**kernel.sysrq = 252**
* Applying /etc/sysctl.d/99-sysctl.conf ...
net.ipv6.conf.all.disable_ipv6 = 1
vm.swappiness = 1
vm.vfs_cache_pressure = 50
* Applying /etc/sysctl.conf ...
net.ipv6.conf.all.disable_ipv6 = 1
vm.swappiness = 1
vm.vfs_cache_pressure = 50
gooeygirl@linux-Tower:~>
Thanks so much for helping me to learn more.