Another major front in the war between plaintiffs and corporate defendants over the high costs of litigation has opened up in an obscure corner of judicial bureaucracy: proposed changes to the Federal Rules of Civil Procedure.

More than 2,200 lawyers and others took the time in recent weeks to file sometimes impassioned ­comments with a committee of the Judicial Con­ference over proposals to narrow pretrial discovery and ease sanctions for failure to preserve documents. The deadline for comments was Feb. 18.