A signature occurs when the Member's name appears on the official list maintained by the Clerk of the U.S. House of Representatives. The signature must be recorded and published in accordance with House rules. If a Member signs and then withdraws their signature before or after the petition reaches 218 signatures, this still satisfies the signing requirement. Non-voting Delegates and the Resident Commissioner cannot sign discharge petitions. Party affiliation is determined at the time of signing. If a Member dies or resigns after signing, their signature remains valid unless removed by their successor. For ordinal signature markets (e.g., "Who will provide the 218th signature?"), the market resolves based on which party the Member providing that specific numbered signature belongs to.