Proof of claim by operational creditors in liquidation requires detailed disclosure, supporting documents, and sworn verification. Proof of claim by operational creditors other than workmen and employees in liquidation required Form C submission to the liquidator, with particulars of the creditor, total claim, nature of debt, supporting documents, manner and date of incurrence, mutual dealings, retention of title or other security, assignment details, and bank account details. The claimant also had to attach relied-on documents, sign through an authorised person if applicable, and file an affidavit and verification confirming the debt, the authenticity of documents, and any set-off or security disclosed.