limit[s] sanctions to the signatory attorney and a represented party.” Id. The court thus held that the evidence did not support sanctions against Yuen “because he did not sign the objectionable pleadings and was not a party to those pleadings.” Id. Yuen did not address the situation present in this case—a challenged motion signed by a pro se plaintiff. Instead, Yuen—and the two cases it relied upon construing Rule 13—addressed situations in which the attorney who was sanctioned by the trial court for filing groundless pleadings did not actually sign the challenged pleadings, but rather an associate at the sanctioned attorney’s firm signed the pleadings. See id.; see also In re Hill, No. 2-07-295-CV, 2007 WL 2891059, at *2 (Tex.App.-Fort Worth Oct. 3, 2007, orig. proceeding) (mem.op.) (<HOLDING>); Metzger v. Sebek, 892 S.W.2d 20, 52
holding that courts look to substance of plea for relief to determine nature of pleading not merely title of pleading holding that trial court abused its discretion in sanctioning attorney under rule 13 for signing groundless pleading when associate at attorneys firm was person who signed pleading holding that a court may not apply a heightened pleading standard more stringent than the usual pleading requirements of rule 8 in civil rights cases alleging municipal liability under  1983 holding that a circuit court has discretion under rule 11 to impose attorneys fees on litigants who bring vexatious and groundless lawsuits holding that pleading rules are substantive