[tankenmate]

The geographic protections are mainly at the top level, i.e. you can't apply for a new gTLD of .unitedkingdom for example. The geographic restrictions are mainly in three parts, you can't apply for 2 ASCII character gTLDs (this in effect protects any potential new countries that come into existence). You can't apply for a gTLD that is either the proper full name or short form name of a country or anything that is confusingly similar, i.e. no .unitedstates. And finally if you want to apply for a name that is a city or region name you need at least a letter of non objection from the constituent governments.

Trademark protections come in three parts. At the top level a trademark holder can object to you applying for a TLD that is an exact match for a trademark they hold in any jurisdiction. There are provision for trademark front running as well here. At the second level registries are required to provide protection for trademark holders both at registry start up (sunrise and landrush) as well as for ongoing operations. The protections during sunrise and landrush are stronger than during ongoing operations.

During sunrise and landrush registries are required to restrict registrations that are an exact match to marks in the trademark clearing house. They are also required to implement the Uniform Rapid Suspension (URS) during sunrise and landrush and the first 60 days of general availability. There is also a requirement for the UDRP for ongoing operations but this is almost exactly the same for other existing gTLDs (ccTLDs are a different matter).

Obviously there are corner cases to the above and there are a large number of details involved. If you want more information a good starting point is the Applicant Guidebook which you can get from this link:

http://newgtlds.icann.org/en/applicants/agb

EDIT: added information about UDRP.