Kernel system variables configuration files
Files found under the /etc/sysctl.d directory that end with .conf are
parsed within sysctl(8) at boot time. If you want to set kernel variables
you can either edit /etc/sysctl.conf or make a new file.
The filename isn't important, but don't make it a package name as it may clash
with something the package builder needs later. It must end with .conf though.
My personal preference would be for local system settings to go into
/etc/sysctl.d/local.conf but as long as you follow the rules for the names
of the file, anything will work. See sysctl.conf(8) man page for details
of the format.