Report content
Reports go to platform staff only. The seller of a reported product is never told who filed the report; staff can see the reporter so that a pattern of false reports can be identified.
Report from the page you are looking at
The report form is attached to the content it applies to, so the target is unambiguous.
Open the product page, the seller profile or the review you want to report and use the “Report this …” control on that page. You can also report a listing directly with a link of the form /report?type=PRODUCT&id=<product-id>.
Copyright complaints
A formal copyright notice has to contain more than a report does — identification of the work and of the infringing listing, a good-faith statement and your signature.
Read what a notice must contain