No complaint in any civil action shall contain an ad damnum or monetary amount claimed against any defendant, unless such ad damnum or monetary amount claimed indicates damages which are liquidated or ascertainable by calculation and a statement under oath by a person having knowledge thereof is attached to such complaint setting forth the manner in which the amount of said damages was calculated. For the purposes of this section complaint shall include a claim, crossclaim or counterclaim. In civil actions in the superior court, parties, through their counsel, may suggest a specific monetary amount for damages at trial.
Mass. Gen. Laws ch. 231, § 13B