Statement of Use
Document proving a trademark is being used in commerce.
Detailed Explanation
A Statement of Use (SOU) is a sworn declaration filed with the USPTO for trademark applications filed under the 'intent-to-use' basis. It must be filed within six months of the Notice of Allowance to prove that the mark is now actually being used in commerce with the goods or services listed. It requires submitting a specimen (example) of the mark as used in the marketplace.