second level domains

I am trying to find out why you can't register certain acronyms for second level domains.. Some I understand......like: Opec, Interpol, unesco, UN etc etc etc but when it comes to more generic acronyms like Eco, SPC, LAS etc etc it left me scratching my head...... If someone can let me know...

I am trying to find out why you can't register certain acronyms for second level domains.. Some I understand......like: Opec, Interpol, unesco, UN etc etc etc but when it comes to more generic acronyms like Eco, SPC, LAS etc etc it left me scratching my head...... If someone can let me know...

It seems to be a good domain hack for the word 'income' but being a second level domain has confused me! :confused: can you guys please appraise this domain for me? Also give your views on these kind of domains,are they worth registration? inco.me.uk

It seems to be a good domain hack for the word 'income' but being a second level domain has confused me! :confused: can you guys please appraise this domain for me? Also give your views on these kind of domains,are they worth registration? inco.me.uk