Ensure all systems from EKI's page is entered

In GitLab by @ronaldtse on Feb 24, 2020, 22:57

http://www.eki.ee/isotc46wg3/linksscr.htm

NOTE: I have previously asked Peeter about KNAB's systems (EKI's place name database), he advised against encoding them, but I have doubts because data encoding is also a valid use case. Will ask again.