A person shall not be registered as proprietor until, if required by the registrar, he has produced to him such documents of title, if any, as will, in the opinion of the registrar, when stamped or otherwise marked, give notice to any purchaser or other person dealing with the land of the fact of the registration, and the registrar shall stamp or otherwise mark the same accordingly, unless the registrar is satisfied that without such stamping or marking the fact of such registration cannot be concealed from a purchaser or other person dealing with the land:

Provided that, in the case of registration with a possessory title, the registrar may act on such reasonable evidence as may be prescribed as to the sufficiency of the documents produced, and as to dispensing with their production in special circumstances.