Rule 305. Summons; supplemental summons, amendment. (a) Summons; supplemental summons. A summons shall specify the basis of the venue designated and if based upon the residence of the plaintiff it shall specify the plaintiff's address, and also shall bear the index number assigned and the date of filing with the clerk of the court. A third-party summons shall also specify the date of filing of the third-party summons with the clerk of the court. The summons in an action arising out of a consumer credit transaction shall prominently display at the top of the summons the words "consumer credit transaction" and, where a purchaser, borrower or debtor is a defendant, shall specify the county of residence of a defendant, if one resides within the state, and the county where the consumer credit transaction took place, if it is within the state. Where, upon order of the court or by stipulation of all parties or as of right pursuant to section 1003, a new party is joined in the action and the joinder is not made upon the new party's motion, a supplemental summons specifying the pleading which the new party must answer shall be filed with the clerk of the court and served upon such party. (b) Summons and notice. If the complaint is not served with the summons, the summons shall contain or have attached thereto a notice stating the nature of the action and the relief sought, and, except in an action for medical malpractice, the sum of money for which judgment may be taken in case of default. (c) Amendment. At any time, in its discretion and upon such terms as it deems just, the court may allow any summons or proof of service of a summons to be amended, if a substantial right of a party against whom the summons issued is not prejudiced.