PITTSBURGH - Citing the principle of comity, a Pennsylvania federal judge on Dec. 30 remanded a class complaint that accuses a large retailer of improperly charging sales tax on the sales price prior to coupons being applied (Brian Farneth, et al. v. Wal-Mart Stores, Inc., t/d/b/a Wal-Mart, No. 13-1062, W.D. Pa.; 2013 U.S. Dist. LEXIS 181020).