875—173.26 (90A) Contracts. All contracts between promoters and contestants shall be written on official forms furnished by the commissioner. One copy of each contract shall be filed with the commissioner at least seven days prior to the date of the bout, unless a specific individual delay is approved by the commissioner. Telegrams or letters indicating acceptance of terms will be considered an agreement between a contestant, the contestant’s manager and the promoter pending the actual signing of the contract.