In the United Kingdom, we have a whole slab of second-level domains for specific purposes. .ac.uk for educational establishments beyond school, .sch.uk for schools, and .bl.uk for the national library. On top of that we even have ones like .police.uk, .parliament.uk, and soon .judiciary.uk. I believe Japan has a system like this too. I can't seeing it getting much use in either. Then again, not every country has this, so it probably should be released.
South Africa has a similar system, with .ac.za for academic and tertiary institutions, .city.za for municipal governments, .co.za for commercial and generic registrations, .edu.za for distance-learning institutions, .gov.za for government departments, .mil.za for the military, .school.za for schools (with provincial sub-levels like .wcape.school.za) and .org.za for non-commercial entities. It removes the need to have a .edu domain when .ac.za suffices.
It’s always interesting to browser Mozilla’s public suffix list to see all the weird and wonderful second level domains around the world: http://publicsuffix.org/list/
