As to the proper procedure, You can provide any sort of cover letter but the information that must be included in a claim of copyright under the DMCA... 1. Name, address, telephone number, and email address of the owner of the information. 2. A physical or electronic signature of the owner of an exclusive right that has been allegedly infringed, or a person authorized to act on behalf of the owner. 3. Identification of the copyrighted work claimed to have been infringed, or, if multiple such works at a single online site are covered by a single notification, a representative list of such works at that site, including any copyright registration (if applicable). 4. Information such as all headers containing time stamps reasonably sufficient to permit location of the material. 5. Please indicate if you are aware of how long the infringing activity is taking place and if you have knowledge that the activity is currently taking place. 6. Please provide your name, address and telephone number.