1. In interpleader proceedings, the claimant is construed as the plaintiff for purposes of Rule 32(12), and therefore the proviso requiring written consent applies to any joinder application seeking to add persons as claimants/plaintiffs. An oral application for joinder without such written consent is non-compliant with the Rules. 2. Where a claimant in interpleader proceedings admits that attached property belongs to third parties and not to himself, the claimant lacks locus standi to claim such property. 3. Where a party lacks locus standi, the appropriate order is to strike the claim from the roll rather than dismiss it. Dismissal is only appropriate where the court has examined the merits of a claim. Striking off preserves the right of properly interested parties to approach the court for relief and protects access to justice. 4. The presumption of ownership arising from possession cannot be applied mechanically where there are admissions and evidence suggesting no connection between the attached property and the judgment debtors, particularly where the judgment debtors had vacated the premises and the property is registered to third parties.