What is Trademark Clearinghouse?

Question
What is Trademark Clearinghouse (TMCH)?
Answer
Trademark protection is one of the core principles of the release of new extensions. In order to have a uniform process in trademark validation, ICANN appointed the Trademark Clearinghouse (TMCH) to provide a centralized database of verified trademarks, that is connected to each and every new TLD that will launch.
Initially, a validated trademark only provided priority over domain registrations in the so-called Sunrise phases, but over time additional services (like "protected marks lists") have been introduced which use the services of the TMCH to check existence validity of a trademark.
If you are, or your customer is, a trademark holder and want to benefit from the priority treatments of new extensions, the first step is to let the TMCH validate your trademark.