(a) Signature. Every pleading, written motion, and other paper, served on another party or filed or submitted to the court shall be signed by an attorney, or by a party if the party is not represented by an attorney, with the name of the attorney or party clearly printed or typed directly below the signature. Absent good cause shown, the court shall strike any unsigned paper if the omission of the signature is not corrected promptly after being called to the attention of the attorney or party. (b)