23. Before being questioned, a witness shall swear that he will tell the truth.
He shall be exempted from this formality if he does not understand the nature of the oath; in such a case, he shall nevertheless be informed of his obligation to tell the truth.
The witness must then state his name and address.
O.C. 217-2000, s. 25; O.C. 618-2007, s. 22.