Yellow Freight refers to a line of cases related to the Commonwealth Court’s 1981 Decision in Yellow Freight Sys., Inc. v. WCAB (Madara), 423 A.2d 1125 (Pa. Commw. 1981) that defined the significant negative ramifications for the untimely filing of an Answer to Claim Petition. An Answer to Claim Petition must be filed no later than the 20th day...