I suggest NOT to click on the link to definition of the Trademark Clearinghouse down this page (dated May 2011) but to refer to last version of the Applicant Guidebook (dated September 2001).
"details...details"...
A blog about New gTLDs and dotBrands (.BRANDs) from the ICANN new gTLD program. You can subscribe to The gTLD Club's Newsletter.