The Confirmation Number is a four digit number (e.g., 1234) and can be obtained by looking up the application number in the Public Patent Application Information Retrieval (PAIR) or Patent Center systems. If the Confirmation Number is not available or not known, the Third-Party Submission cannot be filed electronically and may be filed in paper instead. Instructions on how to file a third-party submission in paper are available at: https://www.uspto.gov/sites/default/files/documents/3prsubmission_instructions.pdf