Refusal to grant registration: Board must give applicant opportunity to explain on prima facie objection before final decision. When the Board is of the prima facie opinion that registration ought not be granted it must communicate reasons and allow the applicant an opportunity to explain, with the initial communication issued within a prescribed timeframe excluding time allowed for additional submissions; after considering any explanation the Board must, within a further prescribed period, either accept and issue the certificate of registration or reject the application by order giving reasons.