17. The application of the seal of the Trustees shall be authenticated by the signature of the chair of the Trustees or some other Trustee authorised by the Trustees to authenticate the application of the seal, and of the Clerk or some person authorised by the Trustees to act in that behalf.
18. The Trustees may authorise a person to act instead of the Clerk under paragraph 17 whether or not the Clerk is absent or incapable of acting.
19. Any notice, licence or other document given or issued by the Trustee shall, unless the contrary intention is expressed, be sufficiently authorised if signed by the Clerk or a Trustee appointed for that purpose by the Trustees.