One of the interesting/horrifying things I see as part of my work in Domain Generation Algorithms is the horrifying things people do to their zone files and bizarre DNS server implementations out there. DNS as a protocol has been around a long time and its core to how the Internet works. As such, every update to DNS servers have included backwards compatibility that have left some inefficiencies and gaps that the community is seeking to close. Accordingly, on 1 February 2019, they announced DNS Flag Day. That will be the day for a coordinated release of DNS software to remove support for incompatible implentations of DNS server software that are still operating out there (and often causing problems).