Immediately before the testing clause of any conveyance of lands, it shall be competent to insert a clause of direction, in or as nearly as may be in the form No. 1 of schedule (F.) hereto annexed, specifying the part or parts of the conveyance which the grantor thereof desires to be recorded in the register of sasines; and when such clause is so inserted in any conveyance, whether dated before or after the commencement of this Act, and F2... is presented to the keeper of the appropriate register of sasines for registration, F1the keeper may record such part or parts only, together with the clause of direction and the testing clause F2...: Provided that, notwithstanding such clause of direction, it shall be competent for the person entitled to present the conveyance for registration to record the whole conveyance, F2....